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Abstract:

The present invention provides a photoresist composition comprising a
resin, an acid generator and a compound represented by the formula (C1):
##STR00001##
wherein Rc1 represents an aromatic group which can have one or more
substituents, Rc2 and Rc3 independently each represent a
hydrogen atom, an aliphatic hydrocarbon group which can have one or more
substituents or an aromatic group which can have one or more
substituents, Rc4 and RC6 independently each represent a
hydrogen atom or an aliphatic hydrocarbon group which can have one or
more substituents, or Rc4 and Rc6 are bonded each other to form
an alkanediyl group, Rc5 represents an aliphatic hydrocarbon group
which can have one or more substituents or an amino group which can have
one or two substituents, Rc7 represents a hydrogen atom or an
aliphatic hydrocarbon group which can have one or more substituents, or
Rc5 and Rc7 are bonded each other to form an alkanediyl group.

Claims:

1. A photoresist composition comprising a resin, an acid generator and a
compound represented by the formula (C1): ##STR00152## wherein Rc1
represents an aromatic group which can have one or more substituents,
RC2 and Rc3 independently each represent a hydrogen atom, an
aliphatic hydrocarbon group which can have one or more substituents or an
aromatic group which can have one or more substituents, Rc4 and
Rc6 independently each represent a hydrogen atom or an aliphatic
hydrocarbon group which can have one or more substituents, or Rc4
and Rc6 are bonded each other to form an alkanediyl group, Rc5
represents an aliphatic hydrocarbon group which can have one or more
substituents or an amino group which can have one or two substituents,
Rc7 represents a hydrogen atom or an aliphatic hydrocarbon group
which can have one or more substituents, or Rc5 and Rc7 are
bonded each other to form an alkanediyl group.

2. The photoresist composition according to claim 1, wherein the compound
(C1) is a compound represented by the formula (C1-1): ##STR00153##
wherein Rc1 is the same as defined in claim 1, and Rc8 and
Rc9 independently each represent a C1-C18 alkanediyl group which can
have one or more substituents.

3. The photoresist composition according to claim 2, wherein the compound
represented by the formula (C1-1) is a compound represented by the
formula (C1-1-1) or (C1-1-2): ##STR00154## wherein Rc1 is the same
as defined in claim 1.

4. The photoresist composition according to claim 1, wherein the content
of the compound represented by the formula (C1) is 0.01 to 5 parts by
weight per 100 parts by weight of the resin in the photoresist
composition.

5. The photoresist composition according to claim 1, wherein the acid
generator is an acid generator containing one or more fluorine atoms.

6. The photoresist composition according to claim 1, wherein the acid
generator is a salt represented by the formula (B1): ##STR00155##
wherein Q1 and Q2 each independently represent a fluorine atom
or a C1-C6 perfluoroalkyl group, Lb1 represents a single bond or a
C1-C17 divalent saturated hydrocarbon group in which one or more
--CH2-- can be replaced by --O-- or --CO--, Y represents a C1-C18
aliphatic hydrocarbon group which can have one or more substituents, or a
C3-C18 saturated cyclic hydrocarbon group which can have one or more
substituents, and one or more --CH2-- in the aliphatic hydrocarbon
group and the saturated cyclic hydrocarbon group can be replaced by
--O--, --CO-- or --SO2--, and Z+ represents an organic cation.

7. The photoresist composition according to claim 6, wherein Z+ is a
triarylsulfonium cation.

8. The photoresist composition according to claim 6, wherein Y is an
adamantyl group which can have one or more substituents or an
oxoadamantyl group which can have one or more substituents.

9. The photoresist composition according to claim 1, wherein the content
of the acid generator in the photoresist composition is 1 to 20 parts by
weight per 100 parts by weight of the resin.

10. The photoresist composition according to claim 1, wherein the resin
becomes soluble in an alkali aqueous solution by the action of an acid.

11. The photoresist composition according to claim 1 which further
contains 2,6-diisopropylaniline.

12. A process for producing a photoresist pattern comprising the
following steps (1) to (5): (1) a step of applying the photoresist
composition according to claim 1 on a substrate, (2) a step of forming a
photoresist film by conducting drying, (3) a step of exposing the
photoresist film to radiation, (4) a step of baking the exposed
photoresist film, and (5) a step of developing the baked photoresist film
with an alkaline developer, thereby forming a photoresist pattern.

Description:

[0001] This nonprovisional application claims priority under 35 U.S.C.
§119(a) on Patent Application No. 2009-269036 filed in JAPAN on Nov.
26, 2009 and on Patent Application No. 2010-015145 filed in JAPAN on Jan.
27, 2010, the entire contents of which are hereby incorporated by
reference.

FIELD OF THE INVENTION

[0002] The present invention relates to a photoresist composition.

BACKGROUND OF THE INVENTION

[0003] A photoresist composition is used for semiconductor
microfabrication employing a lithography process.

[0004] A photoresist composition usually comprises an acid generator. In
the photoresist composition, a performance deterioration caused by
inactivation of acid which occurs due to post exposure delay can be
diminished by adding a quencher.

[0005] US 2006/0194982 A1 discloses a photoresist composition comprising
2,6-diisopropylaniline as a quencher.

[0006] US 2003/0017415 A1 discloses a photoresist composition comprising
1,5-diazabicyclo[4.3.0]non-5-ene or 2,6-diisopropylaniline as a quencher.

SUMMARY OF THE INVENTION

[0007] The present invention is to provide a photoresist composition.

[0008] The present invention relates to the followings:

<1> A photoresist composition comprising a resin, an acid generator
and a compound represented by the formula (C1):

##STR00002##

wherein Rc1 represents an aromatic group which can have one or more
substituents, Rc2 and Rc3 independently each represent a
hydrogen atom, an aliphatic hydrocarbon group which can have one or more
substituents or an aromatic group which can have one or more
substituents, Rc4 and Rc6 independently each represent a
hydrogen atom or an aliphatic hydrocarbon group which can have one or
more substituents, or Rc4 and Rc6 are bonded each other to form
an alkanediyl group, Rc5 represents an aliphatic hydrocarbon group
which can have one or more substituents or an amino group which can have
one or two substituents, Rc7 represents a hydrogen atom or an
aliphatic hydrocarbon group which can have one or more substituents, or
Rc5 and Rc7 are bonded each other to form an alkanediyl group;
<2> The photoresist composition according to <1>, wherein the
compound (C1) is a compound represented by the formula (C1-1):

##STR00003##

wherein Rc1 is the same as defined in <1>, and Rc8 and
Rc9 independently each represent a C1-C18 alkanediyl group which can
have one or more substituents; <3> The photoresist composition
according to <2>, wherein the compound represented by the formula
(C1-1) is a compound represented by the formula (C1-1-1) or (C1-1-2):

##STR00004##

wherein Rc1 is the same as defined in <1>; <4> The
photoresist composition according to any one of <1> to <3>,
wherein the content of the compound represented by the formula (C1) in
the photoresist composition is 0.01 to 5 parts by weight per 100 parts by
weight of the resin; <5> The photoresist composition according to
any one of <1> to <4>, wherein the acid generator is an acid
generator containing one or more fluorine atoms; <6> The
photoresist composition according to any one of <1> to <5>,
wherein the acid generator is a salt represented by the formula (B1):

##STR00005##

wherein Q1 and Q2 each independently represent a fluorine atom
or a C1-C6 perfluoroalkyl group, Lb1 represents a single bond or a
C1-C17 divalent saturated hydrocarbon group in which one or more
--CH2-- can be replaced by --O-- or --CO--, Y represents a C1-C18
aliphatic hydrocarbon group which can have one or more substituents, or a
C3-C18 saturated cyclic hydrocarbon group which can have one or more
substituents, and one or more --CH2-- in the aliphatic hydrocarbon
group and the saturated cyclic hydrocarbon group can be replaced by
--O--, --CO-- or --SO2--, and Z+ represents an organic cation;
<7> The photoresist composition according to <6>, wherein
Z+ is a triarylsulfonium cation; <8> The photoresist
composition according to <6> or <7>, wherein Y is an
adamantyl group which can have one or more substituents or an
oxoadamantyl group which can have one or more substituents; <9> The
photoresist composition according to any one of <1> to <8>,
wherein the content of the acid generator is 1 to 20 parts by weight per
100 parts by weight of the resin in the photoresist composition;
<10> The photoresist composition according to any one of <1>
to <9>, wherein the resin becomes soluble in an alkali aqueous
solution by the action of an acid; <11> The photoresist composition
according to any one of <1> to <10> which further contains
2,6-diisopropylaniline; <12> A process for producing a photoresist
pattern comprising the following steps (1) to (5):

[0009] (1) a step of applying the photoresist composition according to any
one of <1> to <11> on a substrate,

[0010] (2) a step of forming a photoresist film by conducting drying,

[0011] (3) a step of exposing the photoresist film to radiation,

[0012] (4) a step of baking the exposed photoresist film, and

[0013] (5) a step of developing the baked photoresist film with an
alkaline developer, thereby forming a photoresist pattern.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0014] The photoresist composition of the present invention comprises a
resin, an acid generator and a compound represented by the formula (C1):

##STR00006##

wherein Rc1 represents an aromatic group which can have one or more
substituents, Rc2 and Rc3 independently each represent a
hydrogen atom, an aliphatic hydrocarbon group which can have one or more
substituents or an aromatic group which can have one or more
substituents, Rc4 and Rc6 independently each represent a
hydrogen atom or an aliphatic hydrocarbon group which can have one or
more substituents, or Rc4 and Rc6 are bonded each other to form
an alkanediyl group, Rc5 represents an aliphatic hydrocarbon group
which can have one or more substituents or an amino group which can have
one or two substituents, Rc7 represents a hydrogen atom or an
aliphatic hydrocarbon group which can have one or more substituents, or
Rc5 and Rc7 are bonded each other to form an alkanediyl group
(hereinafter, simply referred to as Compound (C1)).

[0015] First, the resin will be illustrated.

[0016] The resin becomes soluble in an alkali aqueous solution by the
action of an acid. The resin is insoluble or poorly soluble in an alkali
aqueous solution, and has a structural unit derived from a monomer having
an acid-labile group. The resin can be produced by polymerizing one or
more monomers having an acid-labile group.

[0017] In this specification, "an acid-labile group" means a group capable
of being eliminated by the action of an acid.

[0018] Examples of the acid-labile group include a group represented by
the formula (1):

##STR00007##

wherein Ra1, Ra2 and Ra3 independently each represent an
aliphatic hydrocarbon group or a saturated cyclic hydrocarbon group, and
Ra1 and Ra2 can be bonded each other to form a ring together
with a carbon atom to which Ra1 and Ra2 are bonded.

[0019] Examples of the aliphatic hydrocarbon group include a C1-C8 alkyl
group. Specific examples of the C1-C8 alkyl group include a methyl group,
an ethyl group, a propyl group, an isopropyl group, a butyl group, a
pentyl group, a hexyl group, a heptyl group and an octyl group. The
saturated cyclic hydrocarbon group may be monocyclic or polycyclic, and
preferably has 3 to 20 carbon atoms. Examples of the saturated cyclic
hydrocarbon group include a monocyclic alicyclic hydrocarbon group such
as a C3-C20 cycloalkyl group (e.g. a cyclopentyl group, a cyclohexyl
group, a methylcyclohexyl group, a dimethylcyclohexyl group, a
cycloheptyl group and a cyclooctyl group) and a polycyclic alicyclic
hydrocarbon group such as a decahydronaphthyl group, an adamantyl group,
a norbornyl group, a methylnorbornyl group, and the followings:

##STR00008##

[0020] Examples of the ring formed by bonding Ra1 and Ra2 each
other include the following groups and the ring preferably has 5 to 20
carbon atoms.

##STR00009##

wherein Ra3 is the same as defined above.

[0021] The group represented by the formula (1) wherein Ra1, Ra2
and Ra3 independently each represent a C1-C8 alkyl group such as a
tert-butyl group, the group represented by the formula (1) wherein
Ra1 and Ra2 are bonded each other to form an adamantyl ring and
Ra3 is a C1-C8 alkyl group such as a 2-alkyl-2-adamantyl group, and
the group represented by the formula (1) wherein Ra1 and Ra2
are C1-C8 alkyl groups and Ra13 is an adamantyl group such as a
1-(1-adamantyl)-1-alkylalkoxycarbonyl group are preferable.

[0022] The monomer having an acid-labile group is preferably an acrylate
monomer having an acid-labile group in its side chain or a methacryalte
monomer having an acid-labile group in its side chain. In this
specification, "(meth)acrylate monomer" means a monomer having a
structure represented by CH2═CH--CO-- or
CH2═C(CH3)--CO--, and "acrylate monomer" means a monomer
having a structure represented by CH2═CH--CO--, and
"methacrylate monomer" means a monomer having a structure represented by
CH2═C(CH3)--CO--.

[0023] Preferable examples of the monomer having an acid-labile group
include (meth)acrylate monomers having C5-C20 saturated cyclic
hydrocarbon group. As (meth)acrylate monomers having C5-C20 saturated
cyclic hydrocarbon group, preferred are monomers represented by the
formulae (a1-1) and (a1-2):

##STR00010##

wherein Ra4 and Ras each independently represents a hydrogen
atom or a methyl group, Ra6 and Ra7 each independently
represents a C1-C8 aliphatic hydrocarbon group or a C3-C10 saturated
cyclic hydrocarbon group, La1 and La2 each independently
represents *--O-- or *--O--(CH2).sub.k1--CO--O-- in which *
represents a binding position to --CO--, and k1 represents an integer of
1 to 7, m1 represents an integer of 0 to 14 and n1 represents an integer
of 0 to 10.

[0024] The aliphatic hydrocarbon group preferably has 1 to 6 carbon atoms,
and the saturated cyclic hydrocarbon group preferably has 3 to 8 carbon
atoms and more preferably 3 to 6 carbon atoms.

[0025] Examples of the aliphatic hydrocarbon group include a C1-C8 alkyl
group such as a methyl group, an ethyl group, a propyl group, an
isopropyl group, a butyl group, a tert-butyl group, a 2,2-dimethylethyl
group, a 1-methylpropyl group, a 2,2-dimethylpropyl group, a
1-ethylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a
3-methylbutyl group, a 1-propylbutyl group, a pentyl group, a
1-methylpentyl group, a hexyl group, a 1,4-dimethylhexyl group, a heptyl
group, a 1-methylheptyl group and an octyl group. Examples of the
saturated cyclic hydrocarbon group include a cyclohexyl group, a
methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group,
a methylcycloheptyl group, a norbornyl group and a methylnorbornyl group.

[0026] La1 is preferably *--O-- or *--O-- (CH2).sub.f1--CO--O--
in which * represents a binding position to --CO--, and f1 represents an
integer of 1 to 4, and is more preferably *--O-- or
*--O--CH2--CO--O--, and is especially preferably *--O--. La2 is
preferably *--O-- or *--O--(CH2).sub.f1--CO--O-- in which *
represents a binding position to --CO--, and f1 is the same as defined
above, and is more preferably *--O-- or *--O--CH2--CO--O--, and is
especially preferably *--O--.

[0027] In the formula (a1-1), m1 is preferably an integer of 0 to 3, and
is more preferably 0 or 1. In the formula (a1-2), n1 is preferably an
integer of 0 to 3, and is more preferably 0 or 1.

[0028] Particularly when the photoresist composition contains a resin
derived from a monomer having a bulky structure such as a saturated
cyclic hydrocarbon group, the photoresist composition having excellent
resolution tends to be obtained.

[0029] Examples of the monomer represented by the formula (a1-1) include
the followings.

[0031] Examples of the monomer represented by the formula (a1-2) include
the followings.

##STR00028##

[0032] Among them, preferred are 1-ethyl-1-cyclohexyl acrylate and
1-ethyl-1-cyclohexyl methacrylate, and more preferred is
1-ethyl-1-cyclohexyl methacrylate.

[0033] The content of the structural unit derived from a monomer having an
acid-labile group in the resin is usually 10 to 95% by mole, preferably
15 to 90% by mole and more preferably 20 to 85% by mole based on 100% by
mole of all the structural units of the resin.

[0034] Other examples of the monomer having an acid-labile group include a
monomer represented by the formula (a1-3):

##STR00029##

wherein Ra9 represents a hydrogen atom, a C1-C3 aliphatic
hydrocarbon group which can have one or more substituents, a carboxyl
group, a cyano group or a --COORa13 group in which Ra13
represents a C1-C8 aliphatic hydrocarbon group or a C3-C8 saturated
cyclic hydrocarbon group, and the C1-C8 aliphatic hydrocarbon group and
the C3-C8 saturated cyclic hydrocarbon group can have one or more
hydroxyl groups, and one or more --CH2-- in the C1-C8 aliphatic
hydrocarbon group and the C3-C8 saturated cyclic hydrocarbon group can be
replaced by --O-- or --CO--, Ra10, Ra11 and Ra12 each
independently represent a C1-C12 aliphatic hydrocarbon group or a C3-C12
saturated cyclic hydrocarbon group, and Ra10 and Ra11 can be
bonded each other to form a ring together with the carbon atom to which
Ra10 and Ra11 are bonded, and the C1-C12 aliphatic hydrocarbon
group and the C3-C12 saturated cyclic hydrocarbon group can have one or
more hydroxyl groups, and one or more --CH2-- in the C1-C12
aliphatic hydrocarbon group and the C3-C12 saturated cyclic hydrocarbon
group can be replaced by --O-- or --CO--.

[0035] Examples of the substituent include a hydroxyl group. Examples of
the C1-C3 aliphatic hydrocarbon group which can have one or more
substituents include a methyl group, an ethyl group, a propyl group, a
hydroxymethyl group and a 2-hydroxyethyl group. Examples of Ra13
include a methyl group, an ethyl group, a propyl group, a
2-oxo-oxolan-3-yl group and a 2-oxo-oxolan-4-yl group. Examples of
Ra10, Ra11 and Ra12 include a methyl group, an ethyl
group, a cyclohexyl group, a methylcyclohexyl group, a hydroxycyclohexyl
group, an oxocyclohexyl group and an adamantyl group, and examples of the
ring formed by bonding Ra10 and Ra11 each other together with
the carbon atom to which Ra10 and Ra11 are bonded include a
cyclohexane ring and an adamantane ring.

[0037] When the resin has a structural unit derived from the monomer
represented by the formula (a1-3), the photoresist composition having
excellent resolution and higher dry-etching resistance tends to be
obtained.

[0038] When the resin contains the structural unit derived form the
monomer represented by the formula (a1-3), the content of the structural
unit derived from the monomer represented by the formula (a1-3) is
usually 10 to 95% by mole and preferably 15 to 90% by mole and more
preferably 20 to 85% by mole based on total molar of all the structural
units of the resin.

[0039] Other examples of the monomer having an acid-labile group include a
monomer represented by the formula (a1-4):

##STR00030##

wherein R10 represents a hydrogen atom, a halogen atom, a C1-C6
alkyl group or a C1-C6 halogenated alkyl group, R11 is independently
in each occurrence a halogen atom, a hydroxyl group, a C1-C6 alkyl group,
a C1-C6 alkoxy group, a C2-C4 acyl group, a C2-C4 acyloxy group, an
acryloyl group or a methacryloyl group, la represents an integer of 0 to
4, R12 and R13 each independently represent a hydrogen atom or
a C1-C12 hydrocarbon group, Xa2 represents a single bond or a C1-C17
divalent saturated hydrocarbon group in which one or more --CH2--
can be replaced by --O--, --CO--, --S--, --SO2-- or --N(Rc)--
wherein Rc represents a hydrogen atom or a C1-C6 alkyl group, and
which can have one or more substituents, and Ya3 represents a C1-C12
aliphatic hydrocarbon group, a C3-C18 saturated cyclic hydrocarbon group
or a C6-C18 aromatic hydrocarbon group, and the C1-C12 aliphatic
hydrocarbon group, the C2-C18 saturated cyclic hydrocarbon group and the
C6-C18 aromatic hydrocarbon group can have one or more substituents.

[0040] Examples of the halogen atom include a fluorine atom.

[0041] Examples of the C1-C6 alkyl group include a methyl group, an ethyl
group, a propyl group, an isopropyl group, a butyl group, an isobutyl
group, a sec-butyl group, a tert-butyl group, a pentyl group and a hexyl
group, and a C1-C4 alkyl group is preferable and a C1-C2 alkyl group is
more preferable and a methyl group is especially preferable.

[0042] Examples of the C1-C6 halogenated alkyl group include a
trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl
group, a heptafluoroisopropyl group, a nonafluorobutyl group, a
nonafluoro-sec-butyl group, a nonafluoro-tert-butyl group, a
perfluoropentyl group and a perfluorohexyl group.

[0043] Examples of the C1-C6 alkoxy group include a methoxy group, an
ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an
isobutoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy
group and a hexyloxy group, and a C1-C4 alkoxy group is preferable and a
C1-C2 alkoxy group is more preferable and a methoxy group is especially
preferable.

[0044] Examples of the C2-C4 acyl group include an acetyl group, a
propionyl group and a butyryl group, and examples of the C2-C4 acyloxy
group include an acetyloxy group, a propionyloxy group and a butyryloxy
group.

[0045] Examples of the C1-C12 hydrocarbon group include a C1-C12 aliphatic
hydrocarbon group such as a methyl group, an ethyl group, a propyl group,
an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group,
a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an
octyl group, a 2-ethylhexyl group, a nonyl group, a decyl group, an
undecyl group and a dodecyl group, and a C3-C12 saturated cyclic
hydrocarbon group such as a cyclohexyl group, an adamantyl group, a
2-alkyl-2-adamantyl group, a 1-(1-adamantyl)-1-alkyl group and an
isobornyl group.

[0046] Examples of the C1-C17 divalent saturated hydrocarbon group include
a C1-C17 alkanediyl group such as a methylene group, an ethylene group, a
propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl
group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an
octane-1,8-diyl group, a nonane-1,9-diyl group, a decane-1,10-diyl group,
a undecane-1,11-diyl group, a dodecane-1,12-diyl group, a
tridecane-1,13-diyl group, a tetradecane-1,14-diyl group, a
pentadecane-1,15-diyl group, a hexadecane-1,16-diyl group and a
heptadecane-1,17-diyl group, and a cyclohexane-1,4-diyl group. Examples
of the substituents of the C1-C17 divalent saturated hydrocarbon group
include a halogen atom such as a fluorine atom, and a hydroxyl group.
Examples of the substituted C1-C17 divalent saturated hydrocarbon group
include the followings.

##STR00031##

[0047] Examples of the C1-C17 divalent saturated hydrocarbon group in
which one or more --CH2-- are replaced by --O--, --CO--, --S--,
--SO2-- or --N(Rc)-- include the followings.

##STR00032##

[0048] Examples of the C1-C12 aliphatic hydrocarbon group include a methyl
group, an ethyl group, a propyl group, an isopropyl group, a butyl group,
an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group,
a hexyl group, a heptyl group, an octyl group, a 2-ethylhexyl group, a
nonyl group, a decyl group, an undecyl group and a dodecyl group.
Examples of the C3-C18 saturated cyclic hydrocarbon group include a
cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl
group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a
cyclodecyl group, a norbornyl group, a 1-adamantyl group, a 2-adamantyl
group, an isobornyl group and the following groups.

##STR00033##

[0049] Examples of the C6-C18 aromatic hydrocarbon group include a phenyl
group, a naphthyl group, an anthryl group, a p-methylphenyl group, a
p-tert-butylphenyl group and a p-adamantylphenyl group.

[0050] Examples of the monomer represented by the formula (a1-4) include
the followings.

##STR00034## ##STR00035## ##STR00036## ##STR00037##

[0051] When the resin contains the structural unit derived form the
monomer represented by the formula (a1-4), the content of the structural
unit derived from the monomer represented by the formula (a1-4) is
usually 10 to 95% by mole and preferably 15 to 90% by mole and more
preferably 20 to 85% by mole based on total molar of all the structural
units of the resin.

[0052] The resin can have two or more kinds of structural units derived
from the monomers having an acid-labile group.

[0053] The resin preferably contains the structural unit derived from the
monomer having an acid-labile group and a structural unit derived from
the monomer having no acid-labile group. The resin can have two or more
kinds of structural units derived from the monomers having no acid-labile
group. When the resin contains the structural unit derived from the
monomer having an acid-labile group and the structural unit derived from
the monomer having no acid-labile group, the content of the structural
unit derived from the monomer having an acid-labile group is usually 10
to 80% by mole and preferably 20 to 60% by mole based on total molar of
all the structural units of the resin. The content of the structural unit
derived from a monomer having an adamantyl group, especially the monomer
represented by the formula (a1-1) in the structural unit derived from the
monomer having no acid-labile group, is preferably 15% by mole or more
from the viewpoint of dry-etching resistance of the photoresist
composition.

[0054] The monomer having no acid-labile group preferably contains one or
more hydroxyl groups or a lactone ring. When the resin contains the
structural unit derived from the monomer having no acid-labile group and
having one or more hydroxyl groups or a lactone ring, a photoresist
composition having good resolution and adhesiveness of photoresist to a
substrate tends to be obtained.

[0055] Examples of the monomer having no acid-labile group and having one
or more hydroxyl groups include a monomer represented by the formula
(a2-0):

##STR00038##

wherein R8 represents a hydrogen atom, a halogen atom, a C1-6 alkyl
group or a C1-C6 halogenated alkyl group, R9 is independently in
each occurrence a halogen atom, a hydroxyl group, a C1-C6 alkyl group, a
C1-C6 alkoxy group, a C2-C4 acyl group, a C2-C4 acyloxy group, an
acryloyl group or a methacryloyl group, ma represents an integer of 0 to
4, and a monomer represented by the formula (a2-1):

##STR00039##

wherein Ra14 represents a hydrogen atom or a methyl group, Ra15
and Ra16 each independently represent a hydrogen atom, a methyl
group or a hydroxyl group, La3 represents *--O-- or
*--O--(CH2).sub.k2--CO--O-- in which * represents a binding position
to --CO--, and k2 represents an integer of 1 to 7, and o1 represents an
integer of 0 to 10.

[0056] When KrF excimer laser (wavelength: 248 nm) lithography system, or
a high energy laser such as electron beam and extreme ultraviolet is used
as an exposure system, the resin containing the structural unit derived
from the monomer represented by the formula (a2-0) is preferable, and
when ArF excimer laser (wavelength: 193 nm) is used as an exposure
system, the resin containing the structural unit derived from the monomer
represented by the formula (a2-1) is preferable.

[0057] In the formula (a2-0), examples of the halogen atom include a
fluorine atom, examples of the C1-C6 alkyl group include a methyl group,
an ethyl group, a propyl group, an isopropyl group, a butyl group, an
isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group and
a hexyl group, and a C1-C4 alkyl group is preferable and a C1-C2 alkyl
group is more preferable and a methyl group is especially preferable.
Examples of the C1-C6 halogenated alkyl group include a trifluoromethyl
group, a pentafluoroethyl group, a heptafluoropropyl group, a
heptafluoroisopropyl group, a nonafluorobutyl group, a
nonafluoro-sec-butyl group, a nonafluoro-tert-butyl group, a
perfluoropentyl group and a perfluorohexyl group. Examples of the C1-C6
alkoxy group include a methoxy group, an ethoxy group, a propoxy group,
an isopropoxy group, a butoxy group, an isobutoxy group, a sec-butoxy
group, a tert-butoxy group, a pentyloxy group and a hexyloxy group, and a
C1-C4 alkoxy group is preferable and a C1-C2 alkoxy group is more
preferable and a methoxy group is especially preferable. Examples of the
C2-C4 acyl group include an acetyl group, a propionyl group and a butyryl
group, and examples of the C2-C4 acyloxy group include an acetyloxy
group, a propionyloxy group and a butyryloxy group. In the formula
(a2-0), ma is preferably 0, 1 or 2, and is more preferably 0 or 1, and
especially preferably 0.

[0058] The resin containing the structural unit derived from the monomer
represented by the formula (a2-0) and the structural unit derived from
the compound having an acid generator can be produced, for example, by
polymerizing the compound having an acid generator and a monomer obtained
by protecting a hydroxyl group of the monomer represented by the formula
(a2-0) with an acetyl group followed by conducting deacetylation of the
obtained polymer with a base.

[0059] Examples of the monomer represented by the formula (a2-0) include
the followings.

##STR00040## ##STR00041## ##STR00042## ##STR00043##

[0060] Among them, preferred are 4-hydroxystyrene and
4-hydroxy-α-methylstyrene.

[0061] When the resin contains the structural unit derived from the
monomer represented by the formula (a2-0), the content of the structural
unit derived from the monomer represented by the formula (a2-0) is
usually 5 to 90% by mole and preferably 10 to 85% by mole and more
preferably 15 to 80% by mole based on total molar of all the structural
units of the resin.

[0062] In the formula (a2-1), Ra14 is preferably a methyl group,
Ra15 is preferably a hydrogen atom, Ra16 is preferably a
hydrogen atom or a hydroxyl group, La3 is preferably *--O-- or
*--O-- (CH2).sub.f2--CO--O-- in which * represents a binding
position to --CO--, and f2 represents an integer of 1 to 4, and is more
preferably *--O--, and o1 is preferably 0, 1, 2 or 3 and is more
preferably 0 or 1.

[0063] Examples of the monomer represented by the formula (a2-1) include
the followings, and 3-hydroxy-1-adamantyl acrylate, 3-hydroxy-1-adamantyl
methacrylate, 3,5-dihydroxy-1-adamantyl acrylate,
3,5-dihydroxy-1-adamantyl methacrylate,
1-(3,5-dihydroxy-1-adamantyloxycarbonyl)methyl acrylate and
1-(3,5-dihydroxy-1-adamantyloxycarbonyl)methyl methacrylate are
preferable, and 3-hydroxy-1-adamantyl methacrylate and
3,5-dihydroxy-1-adamantyl methacrylate are more preferable.

##STR00044## ##STR00045## ##STR00046## ##STR00047## ##STR00048##

[0064] When the resin contains the structural unit derived from the
monomer represented by the formula (a2-1), the content of the structural
unit derived from the monomer represented by the formula (a2-1) is
usually 3 to 40% by mole and preferably 5 to 35% by mole and more
preferably 5 to 30% by mole based on total molar of all the structural
units of the resin.

[0065] Examples of the lactone ring of the compound having no acid-labile
group and having a lactone ring include a monocyclic lactone ring such as
β-propiolactone ring, γ-butyrolactone ring and
γ-valerolactone ring, and a condensed ring formed from a monocyclic
lactone ring and the other ring. Among them, preferred are
γ-butyrolactone ring and a condensed lactone ring formed from
γ-butyrolactone ring and the other ring.

[0066] Preferable examples of the monomer having no acid-labile group and
a lactone ring include the monomers represented by the formulae (a3-1),
(a3-2) and (a3-3):

##STR00049##

wherein La4, La5 and La6 each independently represent
*--O-- or *--O--(CH2).sub.k3-CO--O-- in which * represents a binding
position to --CO-- and k3 represents an integer of 1 to 7, Ra18,
Ra19 and Ra20 each independently represent a hydrogen atom or a
methyl group, Ra21 represents a C1-C4 aliphatic hydrocarbon group,
Ra22 and Ra23 are independently in each occurrence a carboxyl
group, a cyano group or a C1-C4 aliphatic hydrocarbon group, and p1
represents an integer of 0 to 5, q1 and r1 independently each represent
an integer of 0 to 3.

[0067] It is preferred that La4, La5 and La6 each
independently represent --O-- or *--O--(CH2).sub.d1--CO--O-- in
which * represents a binding position to --CO-- and d1 represents an
integer of 1 to 4, and it is more preferred that La4, La5 and
La6 are *--O--. Ra18, Ra19 and Ra20 are preferably
methyl groups. Ra21 is preferably a methyl group. It is preferred
that Ra22 and Ra23 are independently in each occurrence a
carboxyl group, a cyano group or a methyl group. It is preferred that p1
is an integer of 0 to 2, and it is more preferred that p1 is 0 or 1. It
is preferred that q1 and r1 independently each represent an integer of 0
to 2, and it is more preferred that q1 and r1 independently each
represent 0 or 1.

[0068] Examples of the monomer represented by the formula (a3-1) include
the followings.

##STR00050## ##STR00051## ##STR00052## ##STR00053##

[0069] Examples of the monomer represented by the formula (a3-2) include
the followings.

[0072] When the resin contains the structural unit derived from the
monomer having no acid-labile group and having a lactone ring, the
content thereof is usually 5 to 50% by mole and preferably 10 to 45% by
mole and more preferably 15 to 40% by mole based on total molar of all
the structural units of the resin.

[0073] The resin can contain a structural unit derived from a monomer
having an acid-labile group containing a lactone ring. Examples of the
monomer having an acid-labile group containing a lactone ring include the
followings.

##STR00065## ##STR00066##

[0074] Examples of the other monomer having no acid-labile group include
the monomers represented by the formulae (a4-1), (a4-2), (a4-3) and
(a4-4):

##STR00067##

wherein Ra25 and Ra26 each independently represents a hydrogen
atom, a C1-C3 aliphatic hydrocarbon group which can have one or more
substituents, a carboxyl group, a cyano group or a --COORa27 group
in which Ra27 represents a C1-C36 aliphatic hydrocarbon group or a
C3-C36 saturated cyclic hydrocarbon group, and one or more --CH2--
in the C1-C36 aliphatic hydrocarbon group and the C3-C36 saturated cyclic
hydrocarbon group can be replaced by --O-- or --CO--, with the proviso
that the carbon atom bonded to --O-- of --COO-- of Ra27 is not a
tertiary carbon atom, or Ra25 and Ra26 are bonded together to
form a carboxylic anhydride residue represented by
--C(═O)OC(═O)--.

[0075] Examples of the substituent of the C1-C3 aliphatic hydrocarbon
group include a hydroxyl group. Examples of the C1-C3 aliphatic
hydrocarbon group which can have one or more substituents include a C1-C3
alkyl group such as a methyl group, an ethyl group and a propyl group,
and a C1-C3 hydroxyalkyl group such a hydroxymethyl group and a
2-hydroxyethyl group. The C1-C36 aliphatic hydrocarbon group represented
by Ra27 is preferably a C1-C8 aliphatic hydrocarbon group and is
more preferably a C1-C6 aliphatic hydrocarbon group.

[0076] The C3-C36 saturated cyclic hydrocarbon group represented by
Ra27 is preferably a C4-C36 saturated cyclic hydrocarbon group, and
is more preferably C4-C12 saturated cyclic hydrocarbon group. Examples of
Ra27 include a methyl group, an ethyl group, a propyl group, a
2-oxo-oxolan-3-yl group and a 2-oxo-oxolan-4-yl group.

[0078] The content of the structural unit derived from a monomer
represented by the formula (a4-1), (a4-2) or (a4-3) is usually 0 to 40%
by mole, preferably 3 to 30% by mole and more preferably 5 to 20% by mole
based on total molar of all the structural units of the resin.

[0079] Preferable resin is a resin containing the structural units derived
from the monomer having an acid-labile group, and the structural units
derived from the monomer having one or more hydroxyl groups and/or the
monomer having a lactone ring. The monomer having an acid-labile group is
preferably the monomer represented by the formula (a1-1) or the monomer
represented by the formula (a1-2), and is more preferably the monomer
represented by the formula (a1-1). The monomer having one or more
hydroxyl groups is preferably the monomer represented by the formula
(a2-1), and the monomer having a lactone ring is preferably the monomer
represented by the formula (a3-1) or (a3-2).

[0080] The resin can be produced according to known polymerization methods
such as radical polymerization.

[0081] The resin usually has 2,500 or more of the weight-average molecular
weight, and preferably 3,000 or more of the weight-average molecular
weight. The resin usually has 50,000 or less of the weight-average
molecular weight, and preferably has 30,000 or less of the weight-average
molecular weight. The weight-average molecular weight can be measured
with gel permeation chromatography.

[0082] The content of the resin is preferably 80% by weight or more based
on 100% by weight of the solid component. In this specification, "solid
component" means components other than solvent in the photoresist
composition.

[0083] Next, the acid generator will be illustrated.

[0084] The photoresist composition of the present invention contains one
or more acid generators, and preferably a photoacid generator.

[0085] The acid generator is a substance which is decomposed to generate
an acid by applying a radiation such as a light, an electron beam or the
like on the substance itself or on a photoresist composition containing
the substance. The acid generated from the acid generator acts on the
resin resulting in cleavage of the acid-labile group existing in the
resin.

[0086] Examples of the acid generator include a nonionic acid generator,
an ionic acid generator and the combination thereof. An ionic acid
generator is preferable. Examples of the nonionic acid generator include
an organo-halogen compound, a sulfone compound such as a disulfone, a
ketosulfone and a sulfonyldiazomethane, a sulfonate compound such as a
2-nitrobenzylsulfonate, an aromatic sulfonate, an oxime sulfonate, an
N-sulfonyloxyimide, a sulfonyloxyketone and DNQ 4-sulfonate. Examples of
the ionic acid generator include an acid generator having an inorganic
anion such as BF4.sup.-, PF6.sup.-, AsF6.sup.- and
SbF6.sup.-, and an acid generator having an organic anion such as a
sulfonic acid anion and a bissulfonylimido anion, and an acid generator
having a sulfonic acid anion is preferable. The acid generator containing
one or more fluorine atoms is preferable. Preferable examples of the acid
generator include a salt represented by the formula (B1):

##STR00068##

wherein Q1 and Q2 each independently represent a fluorine atom
or a C1-C6 perfluoroalkyl group, Lb1 represents a single bond or a
C1-C17 divalent saturated hydrocarbon group in which one or more
--CH2-- can be replaced by --O-- or --CO--, Y represents a C1-C18
aliphatic hydrocarbon group which can have one or more substituents, or a
C3-C18 saturated cyclic hydrocarbon group which can have one or more
substituents, and one or more --CH2-- in the aliphatic hydrocarbon
group and the saturated cyclic hydrocarbon group can be replaced by
--O--, --CO-- or --SO2--, and Z+represents an organic cation.

[0087] Examples of the C1-C6 perfluoroalkyl group include a
trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl
group, a nonafluorobutyl group, an undecafluoropentyl group and a
tridecafluorohexyl group, and a trifluoromethyl group is preferable.
Q1 and Q2 each independently preferably represent a fluorine
atom or a trifluoromethyl group, and Q1 and Q2 are more
preferably fluorine atoms.

[0088] Examples of the C1-C17 divalent saturated hydrocarbon group include
a C1-C17 linear alkylene group such as a methylene group, an
ethane-1,2-diyl group, a propane-1,3-diyl group, a propane-1,2-diyl
group, a butane-1,4-diyl group, a butane-1,3-diyl group, a
pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl
group, an octane-1,8-diyl group, a nonane-1,9-diyl group, a
decane-1,10-diyl group, a undecane-1,11-diyl group, a dodecane-1,12-diyl
group, a tridecane-1,13-diyl group, a tetradecane-1,14-diyl group, a
pentadecane-1,15-diyl group, a hexadecane-1,16-diyl group and a
heptadecane-1,17-diyl group, a C1-C17 branched alkylene group such as a
1-methylpropane-1,3-diyl group, a2-methylpropane-1,3-diyl group,
a2-methylpropane-1,2-diyl group, a 1-methylbutane-1,4-diyl group, and a
2-methylbutane-1,4-diyl group,

a divalent saturated monocyclic hydrocarbon group such as a
cycloalkanediyl group such as a cyclobutane-1,3-diyl group, a
cyclopentane-1,3-diyl group, a cyclohexane-1,4-diyl group, and a
cyclooctane-1,5-diyl group, a divalent saturated polycyclic hydrocarbon
group such as a norbornane-1,4-diyl group, a norbornane-2,5-diyl group,
an adamantane-1,5-diyl group and an adamantane-2,6-diyl group, and a
group formed by combining two or more groups selected from the group
consisting of the above-mentioned groups.

[0089] The C1-C17 divalent saturated hydrocarbon group can have one or
more substituents, and examples of the substituent include a halogen
atom, a hydroxyl group, a carboxyl group, a C6-C18 aromatic group, a
C7-C21 aralkyl group such as a benzyl group, a phenethyl group, a
phenylpropyl group, a trityl group, a naphthylmethyl group and a
naphthyethyl group, a C2-C4 acyl group and a glycidyloxy group.

[0090] Examples of the C1-C17 saturated hydrocarbon group in which one or
more --CH2-- are replaced by --O-- or --CO-- include
*--CO--O-Lb2-, *--CO--O-Lb4-CO--O-Lb3-,
*-Lb5-O--CO--, *-Lb7-O-Lb6-, *--CO--O-Lb8-O--, and
*--CO--O-Lb10-O-Lb9-CO--O--, wherein Lb2 represents a
single bond or a C1-C15 alkanediyl group, Lb3 represents a single
bond or a C1-C12 alkanediyl group, Lb4 represents a single bond or a
C1-C13 alkanediyl group, with proviso that total carbon number of
Lb3 and Lb4 is 1 to 13, Lb5 represents a C1-C15 alkanediyl
group, Lb6 represents a C1-C15 alkanediyl group, Lb7 represents
a C10-C15 alkanediyl group, with proviso that total carbon number of
Lb6 and Lb7 is 1 to 16, Lb8 represents a C1-C14 alkanediyl
group, Lb9 represents a C1-C11 alkanediyl group, Lb10
represents a C1-C11 alkanediyl group, with proviso that total carbon
number of Lb9 and Lb10 is 1 to 12, and * represents a binding
position to --C(Q1) (Q2)-. Among them, preferred are
*--CO--O-Lb2-, *--CO--O-Lb4-CO--O-Lb3-, *-Lb5-O--CO--
and *-Lb7-O-Lb6-, and more preferred are *--CO--O-Lb2- and
*--CO--O-Lb4-CO--O-Lb3-, and much more preferred is
*--CO--O-Lb2-, and especially preferred is *--CO--O-Lb2- in
which Lb2 is a single bond or --CH2--.

[0092] The saturated hydrocarbon group can have one or more substituents,
and examples of the substituent include a halogen atom, a hydroxyl group,
a carboxyl group, a C6-C18 aromatic hydrocarbon group, a C7-C21 aralkyl
group such as a benzyl group, a phenethyl group, a phenylpropyl group, a
trityl group, a naphthylmethyl group and a naphthyethyl group, a C2-C4
acyl group and a glycidyloxy group.

[0093] Examples of the substituent in Y include a halogen atom, a hydroxyl
group, an oxo group, a glycidyloxy group, a C2-C4 acyl group, a C1-C12
alkoxy group, a C2-C7 alkoxycarbonyl group, a C1-C12 aliphatic
hydrocarbon group, a C1-C12 hydroxy-containing aliphatic hydrocarbon
group, a C3-C16 saturated cyclic hydrocarbon group, a C6-C18 aromatic
hydrocarbon group, a C7-C21 aralkyl group and
--(CH2).sub.j2--O--CO--Rb1-- in which Rb1 represents a
C1-C16 aliphatic hydrocarbon group, a C3-C16 saturated cyclic hydrocarbon
group or a C6-C18 aromatic hydrocarbon group and j2 represents an integer
of 0 to 4. Examples of the halogen atom include a fluorine atom, a
chlorine atom, a bromine atom and an iodine atom. Examples of the acyl
group include an acetyl group and a propionyl group, and examples of the
alkoxy group include a methoxy group, an ethoxy group, a propoxy group,
an isopropoxy group and a butoxy group. Examples of the alkoxycarbonyl
group include a methoxycarbonyl group, an ethoxycarbonyl group, a
propoxycarbonyl group, an isopropoxycarbonyl group and a butoxycarbonyl
group. Examples of the aliphatic hydrocarbon group include the same as
described above. Examples of the hydroxyl-containing aliphatic
hydrocarbon group include a hydroxymethyl group. Examples of the C3-C16
saturated cyclic hydrocarbon group include the same as described above,
and examples of the aromatic hydrocarbon group include a phenyl group, a
naphthyl group, an anthryl group, a p-methylphenyl group, a
p-tert-butylphenyl group and a p-adamantylphenyl group. Examples of the
aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl
group, a trityl group, a naphthylmethyl group and a naphthylethyl group.

[0094] Examples of the C1-C18 aliphatic hydrocarbon group represented by Y
include a methyl group, an ethyl group, a propyl group, an isopropyl
group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl
group, a pentyl group, a neopentyl group, a 1-methylbutyl group, a
2-methylbutyl group, a 1,2-dimethylpropyl group, a 1-ethylpropyl group, a
hexyl group, a1-methylpentyl group, a heptyl group, an octyl group,
a2-ethylhexyl group, a nonyl group, a decyl group, an undecyl group and a
dodecyl group, and a C1-C6 alkyl group is preferable. Examples of the
C3-C18 saturated cyclic hydrocarbon group represented by Y include the
groups represented by the formulae (Y1) to (Y26):

##STR00070## ##STR00071## ##STR00072##

[0095] Among them, preferred are the groups represented by the formulae
(Y1) to (Y19), and more preferred are the groups represented by the
formulae (Y11), (Y14), (Y15) and (Y19). The groups represented by the
formulae (Y11) and (Y14) are especially preferable.

[0096] Examples of Y having one or more substituents include the
followings:

##STR00073##

[0097] Y is preferably an adamantyl group which can have one or more
substituents, and is more preferably an adamantyl group or an
oxoadamantyl group.

[0098] Among the sulfonic acid anions of the acid generator represented by
the formula (B1), preferred is a sulfonic acid anion having the group
represented by *--CO--O-Lb2-, and more preferred are anions
represented by the formulae (b1-1-1) to (b1-1-9).

##STR00074##

wherein Q1, Q2 and Lb2 are the same as defined above, and
Rb2 and Rb3 each independently represent a C1-C4 aliphatic
hydrocarbon group, preferably a methyl group.

[0099] Specific examples of the sulfonic acid anion include the
followings.

[0101] Examples of the cation part represented by Z+include an onium
cation such as a sulfonium cation, an iodonium cation, an ammonium
cation, a benzothiazolium cation and a phosphonium cation, and a
sulfonium cation and an iodonium cation are preferable, and an
arylsulfonium cation is more preferable.

[0102] Preferable examples of the cation part represented by Z+
include the cations represented by the formulae (b2-1) to (b2-4):

##STR00116##

wherein Rb4, Rb5 and Rb6 each independently represent a
C1-C30 aliphatic hydrocarbon group which can have one or more
substituents selected from the group consisting of a hydroxyl group, a
C1-C12 alkoxy group and a C6-C18 aromatic hydrocarbon group, a C3-C36
saturated cyclic hydrocarbon group which can have one or more
substituents selected from the group consisting of a halogen atom, a
C2-C4 acyl group and a glycidyloxy group, or a C6-C18 aromatic
hydrocarbon group which can have one or more substituents selected from
the group consisting of a halogen atom, a hydroxyl group, a C1-C36
aliphatic hydrocarbon group, a C3-C36 saturated cyclic hydrocarbon group
or a C1-C12 alkoxy group, Rb7 and Rb9 are independently in each
occurrence a hydroxyl group, a C1-C12 aliphatic hydrocarbon group or a
C1-C12 alkoxy group, m4 and n2 independently represents an integer of 0
to 5, Rb9 and Rb10 each independently represent a C1-C36
aliphatic hydrocarbon group or a C3-C36 saturated cyclic hydrocarbon
group, or Rb9 and Rb10 are bonded to form a C2-C11 divalent
acyclic hydrocarbon group which forms a ring together with the adjacent
S+, and one or more --CH2-- in the divalent acyclic hydrocarbon
group may be replaced by --CO--, --O-- or --S--, and Rb11 represents
a hydrogen atom, a C1-C36 aliphatic hydrocarbon group, a C3-C36 saturated
cyclic hydrocarbon group or a C6-C18 aromatic hydrocarbon group,
Rb12 represents a C1-C12 aliphatic hydrocarbon group, a C6-C18
saturated cyclic hydrocarbon group or a C6-C18 aromatic hydrocarbon group
and the aromatic hydrocarbon group can have one or more substituents
selected from the group consisting of a C1-C12 aliphatic hydrocarbon
group, a C1-C12 alkoxy group, a C3-C18 saturated cyclic hydrocarbon group
and an C2-C13 acyloxy group, or Rb11 and Rb12 are bonded each
other to form a C1-C10 divalent acyclic hydrocarbon group which forms a
2-oxocycloalkyl group together with the adjacent --CHCO--, and one or
more --CH2-- in the divalent acyclic hydrocarbon group may be
replaced by --CO--, --O-- or --S--, and Rb13, Rb14, Rb15,
Rb17 and Rb18 each independently represent a hydroxyl group, a
C1-C12 aliphatic hydrocarbon group or a C1-C12 alkoxy group, Lb11
represents --S-- or --O-- and o2, p2, s2 and t2 each independently
represents an integer of 0 to 5, q2 and r2 each independently represents
an integer of 0 to 4, and u2 represents 0 or 1.

[0103] The aliphatic hydrocarbon group represented by Rb9 to
Rb11 has preferably 1 to 12 carbon atoms. The saturated cyclic
hydrocarbon group represented by Rb9 to Rb11 has preferably 3
to 18 carbon atoms and more preferably 4 to 12 carbon atoms.

[0104] Examples of the aliphatic hydrocarbon group, the saturated cyclic
hydrocarbon group and the aromatic hydrocarbon group include the same as
described above. Preferable examples of the aliphatic hydrocarbon group
include a methyl group, an ethyl group, a propyl group, an isopropyl
group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl
group, a hexyl group, an octyl group and a 2-ethylhexyl group. Preferable
examples of the saturated cyclic hydrocarbon group include a cyclopropyl
group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a
cycloheptyl group, a cyclodecyl group, a 2-alkyl-2-adamantyl group, a
1-(1-adamantyl)-1-alkyl group and an isobornyl group. Preferable examples
of the aromatic group include a phenyl group, a 4-methylphenyl group, a
4-ethylphenyl group, a 4-tert-butylphenyl group, a 4-cyclohexylphenyl
group, a 4-methoxyphenyl group, a biphenyl group and a naphthyl group.
Examples of the aliphatic hydrocarbon group having an aromatic
hydrocarbon group include a benzyl group. Examples of the alkoxy group
include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy
group, a butoxy group, a sec-butoxy group, a tert-butoxy group, a
pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group,
a 2-ethylhexyloxy group, a nonyloxy group, a decyloxy group, an
undecyloxy group and a dodecyloxy group.

[0105] Examples of the C3-C12 divalent acyclic hydrocarbon group formed by
bonding Rb9 and Rb10 include a trimethylene group, a
tetramethylene group and a pentamethylene group. Examples of the ring
group formed together with the adjacent S+and the divalent acyclic
hydrocarbon group include a thiolan-1-ium ring (tetrahydrothiphenium
ring), a thian-1-ium ring and a 1,4-oxathian-4-ium ring. A C3-C7 divalent
acyclic hydrocarbon group is preferable.

[0106] Examples of the C1-C10 divalent acyclic hydrocarbon group formed by
bonding Rb11 and Rb12 include a methylene group, an ethylene
group, a trimethylene group, a tetramethylene group and a pentamethylene
group and examples of the ring group include the followings.

##STR00117##

[0107] Among the above-mentioned cations, the cation represented by the
formula (b2-1) is preferable, and the cation represented by the formula
(b2-1-1) is more preferable and a triphenylsulfonium cation is especially
preferable.

##STR00118##

wherein Rb19, Rb20 and Rb21 are independently in each
occurrence a hydroxyl group, a C1-C36 aliphatic hydrocarbon group, a
C3-C36 saturated cyclic hydrocarbon group or a C1-C12 alkoxy group, and
one or more hydrogen atoms in the aliphatic hydrocarbon group can be
replaced by a hydroxyl group, a C1-C12 alkoxy group or a C6-C18 aromatic
hydrocarbon group, one or more hydrogen atoms of the saturated cyclic
hydrocarbon group can be replaced by a halogen atom, a C2-C4 acyl group
or a glycidyloxy group, and v2, w2 and x2 independently each represent an
integer of 0 to 5. The aliphatic hydrocarbon group preferably has 1 to 12
carbon atoms, and the saturated cyclic hydrocarbon group preferably has 4
to 36 carbon atoms, and it is preferred that v2, w2 and x2 independently
each represent 0 or 1. It is preferred that Rb19, Rb20 and
Rb21 are independently halogen atom (preferably a fluorine atom), a
hydroxyl group, a C1-C12 alkyl group or a C1-C12 alkoxy group.

[0108] Examples of the cation represented by the formula (b2-1) include
the followings.

##STR00119## ##STR00120## ##STR00121##

[0109] Examples of the cation represented by the formula (b2-2) include
the followings.

##STR00122##

[0110] Examples of the cation represented by the formula (b2-3) include
the followings.

##STR00123## ##STR00124## ##STR00125##

[0111] Examples of the cation represented by the formula (b2-4) include
the followings.

[0112] Examples of the salt represented by the formula (B1) include a salt
wherein the anion part is any one of the above-mentioned anion part and
the cation part is any one of the above-mentioned cation part. Preferable
examples of the salt include a combination of any one of anions
represented by the formulae (b1-1-1) to (b1-1-9) and the cation
represented by the formulae (b2-1-1), and a combination of any one of
anions represented by the formulae (b1-1-3) to (b1-1-5) and the cation
represented by the formulae (b2-3).

[0113] The salt represented by the formulae (B1-1) to (B1-17) are
preferable, and the salt represented by the formulae (B1-1), (B1-2),
(B1-6), (B1-11), (B1-12), (B1-13) and (B1-14) are more preferable.

##STR00133## ##STR00134## ##STR00135## ##STR00136## ##STR00137##

[0114] Two or more kinds of the acid generator can be used in combination.

[0115] The content of the acid generator is preferably 1 part by weight or
more and more preferably 3 parts by weight or more per 100 parts by
weight of the resin. The content of the acid generator is preferably 30
parts by weight or less and more preferably 25 parts by weight or less
per 100 parts by weight of the resin.

[0116] Next, Compound (C1) will be illustrated.

[0117] The photoresist composition containing Compound (C1) gives a
photoresist pattern of which a cross-section is nearly a rectangle.
Compound (C1) is used as a quencher.

[0118] In the formula (C1), Rc1 represents an aromatic group which
can have one or more substituents, Rc2 and Rc3 independently
each represent a hydrogen atom, an aliphatic hydrocarbon group which can
have one or more substituents or an aromatic group which can have one or
more substituents, Rc4 and Rc6 independently each represent a
hydrogen atom or an aliphatic hydrocarbon group which can have one or
more substituents, or Rc4 and Rc6 are bonded each other to form
an alkanediyl group, Rc5 represents an aliphatic hydrocarbon group
which can have one or more substituents or an amino group which can have
one or two substituents, Rc7 represents a hydrogen atom or an
aliphatic hydrocarbon group which can have one or more substituents, or
Rc5 and Rc7 are bonded each other to form an alkanediyl group.

[0119] The aromatic group represented by Rc1 may be an aromatic
hydrocarbon group, and may be a heteroaromatic group. Examples of the
aromatic hydrocarbon group include a non-condensed aromatic hydrocarbon
group such as a phenyl group, a biphenyl group, a terphenyl group and a
stilbenzyl group, a condensed aromatic hydrocarbon group such as a
naphthyl group, a phenathryl group, an anthryl group and a pyrenyl group,
a group formed by the condensation of an aromatic group and a
non-aromatic cyclic group such as a 5,6,7,8-tetrahydro-1-naphthyl group,
a 5,6,7,8-tetrahydro-2-naphthyl group, a 9,10-dihydro-1-anthryl group, a
9,10-dihydro-2-anthryl group and a 1-fluorenyl group. The heteroaromatic
group may be a condensed heteroaromatic group and a non-condensed
heteroaromatic group. Examples thereof include a sulfur-containing
heteroaromatic group such as thienyl group, a benzo[b]thienyl group, a
naphtho[2,3-b]thienyl group, a thianthrenyl group and a thioxanthenyl
group; a oxygen-containing heteroaromatic group such as a furyl group, a
benzofuryl group, a dibenzofuryl group, a chromenyl group and a xanthenyl
group; a nitrogen-containing heteroaromatic group such as a pyrrolyl
group, an imidazolyl group, a pyrazolyl group, a pyridyl group, a
pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an indolizinyl
group, an isoindolyl group, an indolyl group, an indazolyl group, a
purinyl group, a quinolizinyl group, an isoquinolinyl group, a quinolinyl
group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl
group, a quinazolinyl group, a cinnolinyl group, a pteridinyl group, a
carbazolyl group, a β-carbolinyl group, a phenanthridinyl group, an
acridinyl group, a perimidinyl group, a phenanthryl group and a
phenazinyl group; a heteroaromatic group having two or more kinds of
heteroatoms in the ring such as a phenoxathiinyl group, an isothiazolyl
group, a phenothiazinyl group, an isoxazolyl group, a furazanyl group and
a phenoxazinyl group.

[0120] Examples of the substituent of the aromatic group include a
hydroxyl group, a C1-C4 alkyl group such as a methyl group, an ethyl
group and a propyl group, a C1-C4 alkoxy group such as a methoxy group, a
nitro group, a cyano group, a halogen atom such as a chlorine atom and a
bromine atom, an amino group, an amino group substituted with one or two
groups selected from the group consisting of an alkyl group and an aryl
group such as a dimethylamino group, a diethylamino group and a
phenylamino group, an oxo group, a methylthio group, a group represented
by the following formula (C1a):

##STR00138##

wherein Rc2, Rc3, Rc4, Rc5, Rc6 and Rc7 are
the same as defined above.

[0121] Specific examples of the aromatic group include a 3-methoxyphenyl
group, a 4-methoxyphenyl group, a 2,4-dimethoxyphenyl group, a
2,4,6-trimethoxyphenyl group, a 3,4,5-trimethoxyphenyl group, a
2-bromophenyl group, a 2-chlorophenyl group, a 2,6-dichlorophenyl group,
a 3-cyanophenyl group, a 4-cyanophenyl group, a 4-hydroxyphenyl group, a
2-hydroxyphenyl group, a tolyl group, a xylyl group, a mesityl group, a
nitrophenyl group, a dimethylaminophenyl group, a diethylaminophenyl
group, an aminophenyl group, a diaminophenyl group, a methylthiophenyl
group, a 1-naphthyl group, a 2-naphthyl group, a 1-phenylamino-4-naphthyl
group, 1-methylnaphthyl group, 2-methylnaphthyl group,
1-methoxy-2-naphthyl group, a 2-methoxy-1-naphthyl group, a
1-dimethylamino-2-naphthyl group, a 1,2-dimethyl-4-naphthyl group, a
1,2-dimethyl-6-naphthyl group, a 1,2-dimethyl-7-naphthyl group, a
1,3-dimethyl-6-naphthyl group, a 1,4-dimethyl-6-naphthyl group, a
1,5-dimethyl-2-naphthyl group, a 1,6-dimethyl-2-naphthyl group, a
1-hydroxy-2-naphthyl group, a 2-hydroxy-1-naphthyl group, a
1,4-dihydroxy-2-naphthyl group, a 7-phenathryl group, a 1-anthryl group,
a 2-anthryl group, a 9-anthryl group, a
9,10-dioxo-9,10-dihydroanthracen-2-yl group, a 3-benzo[b]thienyl group, a
5-benzo[b]thienyl group, a 2-benzo[b]thienyl group, a 4-dibenzofuryl
group, a 4-methyl-7-dibenzofuryl group, a 2-xanthenyl group, a
3-xanthenyl group, a 8-methyl-2-xanthenyl group, a 2-phenoxathiinyl
group, a 7-phenoxathiinyl group, a 2-pyrrolyl group, a 3-pyrrolyl group,
a 5-methyl-3-pyrrolyl group, a 2-imidazolyl group, a 4-imidazolyl group,
a 5-imidazolyl group, a 2-methyl-4-imidazolyl group, a
2-ethyl-4-imidazolyl group, a 2-ethyl-5-imidazolyl group, a 3-pyrazolyl
group, a 1-methyl-3-pyrazolyl group, a 1-propyl-4-pyrazolyl group, a
2-pyrazinyl group, a 5,6-dimethyl-2-pyrazinyl group, a 2-indolizinyl
group, a 2-methyl-3-isoindolyl group, a 2-methyl-1-isoindolyl group, a
1-methyl-2-indolyl group, a 1-methyl-3-indolyl group, a
1,5-dimethyl-2-indolyl group, a 1-methyl-3-indazolyl group, a
2,7-dimethyl-8-purinyl group, a 2-methoxy-7-methyl-8-purinyl group, a
2-quinolizinyl group, a 3-isoquinolynyl group, a 6-isoquinolinyl group, a
7-isoquinolinyl group, a 3-methoxy-6-isoquinolynyl group, a 2-quinolyl
group, a 6-quinolyl group, a 7-quinolyl group, a 2-methoxy-3-quinolyl
group, a 2-methoxy-6-quinolyl group, a 6-phthalazinyl group, a
7-phthalazinyl group, a 1-methoxy-6-phthalazinyl group, a
1,4-dimethoxy-6-phthalazinyl group, a 1,8-naphthyridin-2-yl group, a
2-quinoxalinyl group, a 6-quinoxalinyl group, a
2,3-dimethyl-6-quinoxalinyl group, a 2,3-dimethoxy-6-quinoxalinyl group,
a 2-quinazolinyl group, a 7-quinazolinyl group, a
2-dimethylamino-6-quinazolinyl group, a 3-cinnolinyl group, a
6-cinnolinyl group, a 7-cinnolinyl group, a 3-methoxy-7-cinnolinyl group,
a 2-pteridinyl group, a 6-pteridinyl group, a 7-pteridinyl group, a
6,7-dimethoxypteridinyl group, a 2-carbazolyl group, a 3-carbazolyl
group, a 9-methyl-2-carbazolyl group, a 9-methyl-3-carbazolyl group, a
β-carbolin-3-yl group, a 1-methyl-β-carbolin-3-yl group, a
1-methyl-β-carbolin-6-yl group, a 3-phenanthridinyl group, a
2-acridinyl group, a 3-acridinyl group, a 2-perimidinyl group, a
1-methyl-5-perimidinyl group, a 5-phenanthryl group, a 6-phenanthryl
group, a 1-phenazinyl group, a 2-phenazinyl group, a 3-isothiazolyl
group, a 4-isothiazolyl group, a 5-isothiazolyl group, a 2-phenothiazinyl
group, a 3-phenothiazinyl group, a 10-methyl-3-phenothiazinyl group, a
3-isoxazolyl group, a 4-isoxazolyl group, a 5-isoxazolyl group, a
4-methyl-furazanyl group, a 2-phenoxazinyl group and a
10-methyl-2-phenoxazinyl group.

[0122] The aromatic hydrocarbon group is preferable and the non-condensed
aromatic hydrocarbon group is more preferable. The alkyl group and the
halogen atom are preferable as the substituent, and the C1-C4 alkyl group
and the halogen atom are more preferable.

[0123] Examples of the aliphatic hydrocarbon group represented by
Rc2, Rc3, Rc4, Rc5, Rc6 and Rc7 include a
C1-C18 saturated hydrocarbon group and a C2-C18 unsaturated hydrocarbon
group, and a C1-C6 saturated hydrocarbon group and a C2-C6 unsaturated
hydrocarbon group are preferable. Examples of the C1-C18 saturated
hydrocarbon group include a methyl group, an ethyl group, a propyl group,
a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl
group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a
tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl
group, a heptadecyl group, an octadecyl group, an isopropyl group, an
isobutyl group, a sec-butyl group, a tert-butyl group, an isopentyl
group, a 1-methylpentyl group, a 2-ethylbutyl group, a 1,3-dimethylbutyl
group, an isoheptyl group, a 1-methylhexyl group, a 1-methylheptyl group,
a 3-methylheptyl group, a2-ethylhexyl group, a 1,1,3,3-tetramethylbutyl
group, a 1,1,3-trimethylhezyl group, a 1,1,3,3-tetramethylpentyl group, a
1-methylundecyl group and a 1,1,3,3,5,5-hexamethylhexyl group. The C2-C18
unsaturated hydrocarbon group may have one or more double bonds, a triple
bond or both thereof. Examples thereof include an ethenyl group, a
propenyl group, a 2-butenyl group, a 3-butenyl group, an isobutenyl
group, a 3-methyl-2-butenyl group, a 2,4-pentadienyl group, a 2-octenyl
group, a 2-dodecenyl group, an isododecenyl group, an oleyl group, a
2-octadecenyl group, a 4-octadecenyl group, an ethynyl group, a propynyl
group, a 2-butynyl group, a 3-butynyl group, a 2-octynyl group and a
2-octadecynyl group.

[0124] Rc4 and Rc6 can be bonded each other to form an
alkanediyl group, and the ring formed by bonding the alkanediyl group,
the nitrogen atoms to which Rc4 and Rc6 are bonded respectively
and --CH-- is preferably 4- to 21-membered ring, more preferably 5- to
15-membered ring, and especially preferably 5- to 9-membered ring.
Examples of the ring include a 1,3-diazacyclobutane ring, a
1,3-diazacyclopentane ring, a 1,3-diazacyclohexane ring, a
1,3-diazacycloheptane ring, a 1,3-diazacyclooctane ring, a
1,3-diazacyclononane ring, a 1,3-diazacyclodecane ring, a
1,3-diazacycloundecane ring, a 1,3-diazacyclododecane ring, a
1,3-diazacyclotridecane ring, a 1,3-diazacyclotetradecane ring and a
1,3-diazacyclopentadecane ring. These rings may have a hydrocarbon group
such as a C1-C4 alkyl group such as a methyl group, an ethyl group, a
propyl group, an isopropyl group, a butyl group, an isobutyl group, a
sec-butyl group and a tert-butyl group.

[0125] Rc5 and Rc7 can be bonded each other to form an
alkanediyl group, and the ring formed by bonding the alkanediyl group,
the nitrogen atom to which Rc7 is bonded and --CH-- to which
Rc5 is bonded is preferably 3- to 20-membered ring, more preferably
4- to 14-membered ring, and especially preferably 4- to 8-membered ring.
Examples of the ring include an azacyclopropane ring, an azacyclobutane
ring, an azacyclopentane ring, an azacyclohexane ring, an azacycloheptane
ring, an azacyclooctane ring, an azacyclononane ring, an azacyclodecane
ring, an azacycloundecane ring, an azacyclododecane ring, an
azacyclotridecane ring and an azacyclotetradecane ring. These rings may
have a hydrocarbon group such as a C1-C4 alkyl group such as a methyl
group, an ethyl group, a propyl group, an isopropyl group, a butyl group,
an isobutyl group, a sec-butyl group and a tert-butyl group.

[0126] Examples of the substituents of the aliphatic hydrocarbon group
include the same as those of the aromatic group represented by Rc1
to Rc3 other than an alkyl group, and a halogen atom is preferable
as the substituent.

[0127] Examples of the amino group which can have one or two substituents
represented by Rc5 include an amino group, an amino group
substituted with a C1-C18 alkyl group such as a methylamino group, an
ethylamino group, a propylamino group, a butylamino group, a pentylamino
group, a hexylamino group, an octadecylamino group, and an amino group
substituted with two C1-C18 alkyl groups such as a dimethylamino group, a
diethylamino group, a dipropylamino group, a dibutylamino group, a
dipentylamino group, a dihexylamino group, a dioctadecylamino group, a
methylethylamino group, a methylpropylamino group, a methylisopropylamino
group, a methylbutylamino group, a methylisobutylamino group, an
ethylisopropylamino group, a diisopropylamino group, an ethylbutylamino
group, an ethylisobutylamino group, an ethyl-tert-butylamino group, an
isopropylbutylamino group, an isopropylisobutylamino group and a
diisobutylamino group.

[0128] Compound (C1) preferably satisfys the following formula (1):

0.2≦(ΔDa-ΔDb)/(ΔDc-ΔDd)≦0.9 (I)

wherein ΔDa represents an absolute value of the difference
between d1 and da, ΔDb represents an absolute value
of the difference between d1 and db, ΔDC represents
an absolute value of the difference between d1 and dc,
ΔDd represents an absolute value of the difference between
d1 and dd, and d1, da, db, dc and dd
are measured according to the following steps (1) to (6):

[0129] (1) a step of forming the first film consisting of Compound (I) and
a resin having an acid-labile group, being insoluble or poorly soluble in
an alkali aqueous solution but becoming soluble in an alkali aqueous
solution by the action of an acid, followed by measuring the film
thickness d1 of the first film formed,

[0130] (2) a step of forming the second film consisting of an
alkali-soluble resin and an acid having a group represented by
--C(Q3)(Q4)-SO3H wherein Q3 and Q4 independently
each represent a fluorine atom or a C1-C6 perfluoroalkyl group, on the
first film,

[0131] (3) a step of exposing the first and second films formed in the
steps (1) and (2) at the exposure amount of 40 mJ/cm2, followed by
heating them and developing them with an aqueous alkaline solution and
then, measuring the film thickness da of the first film after
development,

[0132] (4) a step of exposing the first and second films formed in the
steps (1) and (2) at the exposure amount of 40 mJ/cm2, followed by
developing them with an aqueous alkaline solution and then, measuring the
film thickness db of the first film after development,

[0133] (5) a step of heating the first and second films formed in the
steps (1) and (2), followed by developing them with an aqueous alkaline
solution and then, measuring the film thickness dc of the first film
after development, and

[0134] (6) a step of developing the first and second films formed in the
steps (1) and (2) with an aqueous alkaline solution and then, measuring
the film thickness dd of the first film after development.

[0135] The film thickness d1, da, db, dc and dd
can be measured, for example, with a contactless film thickness
measurement such as Lambda Ace manufactured by DAINIPPON SCREEN MFG. CO.
LTD.,

[0136] The resin having an acid-labile group, being insoluble or poorly
soluble in an alkali aqueous solution but becoming soluble in an alkali
aqueous solution by the action of an acid means a resin capable of
decomposing with the action of an acid to increase the solubility in an
alkaline developer, and the resin has a group decomposing with the action
of an acid thereby giving an alkali-soluble group by the action of an
acid. Examples of the alkali-soluble group include --COOH, --OH and
--SO3H, and examples of the group decomposing with the action of an
acid include the above-mentioned acid-labile group. Examples of the resin
include the above-mentioned resins and specific examples thereof include
the resin described in JP 2006-257078 A such as the resin having the
structural units derived from the following monomers.

##STR00139##

[0137] In the step (1), a composition consisting of Compound (1), a resin
having an acid-labile group, being insoluble or poorly soluble in an
alkali aqueous solution but becoming soluble in an alkali aqueous
solution by the action of an acid, a quencher and a solvent is
spin-coated over the silicon wafer to prepare a composition layer
followed by drying the layer to give the first film. The drying is
usually conducted with a heating apparatus such as a hot plate, and can
be carried out with a decompressor. The drying temperature is usually 50
to 200° C., and the drying pressure is usually 1 to 1.0*105
Pa. Examples of the solvent include known solvents used in the
photoresist field such as the solvents described in JP 2006-257078 A.
Specific examples thereof include propylene glycol monomethyl ether
acetate, propylene glycol monomethyl ether, 2-heptanone and
γ-butyrolactone. Two or more kinds of the solvents can be used in
combination.

[0138] The alkali-soluble resin in the step (2) means a resin having an
acidic group and having a property of dissolving in an aqueous alkaline
developer by contacting the developer. Examples of the alkali-soluble
resin include the known alkali-soluble resins in the photoresist field
and specific examples thereof include the resin consisting of the
structural unit represented by the formula (III):

##STR00140##

[0139] Examples of the C1-C6 perfluoroalkyl group represented by Q3
and Q4 include the same as described above, and it is preferred that
Q3 and Q4 are independently a fluorine atom or a
trifluoromethyl group, and it is more preferred that Q3 and Q4
are fluorine atoms. Examples of the acid having a group represented by
--C(Q3)(Q4)-SO3H include the acids generated from the acid
generators described in JP 2006-257078 A, and specific examples thereof
include the following.

##STR00141##

[0140] In the step (2), a composition consisting of an alkali-soluble
resin, an acid having a group represented by
--C(Q3)(Q4)-SO3H and a solvent is spin-coated over the
first film formed in the step (1) to prepare a composition layer followed
by drying the layer to give the second film on the first film. The drying
is usually conducted with a heating apparatus such as a hot plate, and
can be carried out with a decompressor. The drying temperature is usually
50 to 200° C., and the drying pressure is usually 1 to
1.0*105 Pa. Examples of the solvent include known solvents used in
the photoresist field such as the solvents described in JP 2006-257078 A.
Specific examples thereof include isobutyl alcohol.

[0141] In the step (3), the exposure is usually conducted with an exposure
system. An immersion exposure system can be used. Examples of the
exposure source include alight source radiating laser light in a
UV-region such as a KrF excimer laser (wavelength: 248 nm), an ArF
excimer laser (wavelength: 193 nm) and a F2 laser (wavelength: 157
nm), and a light source radiating harmonic laser light in a far UV region
or a vacuum UV region by wavelength conversion of laser light from a
solid laser light source (such as YAG or semiconductor laser).

[0142] The temperature of heating of the exposed films is usually 50 to
200° C., and preferably 70 to 150° C.

[0143] The development of the heated films is usually carried out using a
development apparatus. The alkaline developer used may be any one of
various alkaline aqueous solution used in the art. An aqueous solution of
tetramethylammonium hydroxide or (2-hydroxyethyl)trimethylammonium
hydroxide (commonly known as "choline") is often used.

[0144] In the step (3), the acid having a group represented by
--C(Q3)(Q4)-SO3H contained in the second film is moved in
the first and the second films by exposure, and the acid having a group
represented by --C(Q3) (Q4)-SO3H contained in the second
film is also moved in the first and the second films by heating. By
moving the acid having a group represented by
--C(Q3)(Q4)-SO3H by exposure and heating, the resin in the
first film is contacted with the acid and a part of the resin in the
first film becomes an alkali-soluble and it is dissolved in an alkaline
developer on the development. Therefore, the film thickness d' becomes
smaller than the film thickness d1. On the development, the second
film is dissolved in an alkaline developer.

[0145] ΔDa represents an absolute value of the difference
between d1 and da, and ΔDa means the amount of film
thickness loss of the first film by exposure at the exposure amount of 40
mJ/cm2 and heating.

[0146] In the step (4), the exposure is conducted under the same condition
as that of the exposure in the step (3). The development is also
conducted under the same condition as that of the development in the step
(3).

[0147] In the step (4), the acid having a group represented by
--C(Q3)(Q4)-SO3H contained in the second film is also
moved in the first and the second films by exposure. By moving the acid
having a group represented by --C(Q3)(Q4)-SO3H by
exposure, the resin in the first film is contacted with the acid and a
part of the resin in the first film becomes an alkali-soluble and it is
dissolved in an alkaline developer on the development. Therefore, the
film thickness db becomes smaller than the film thickness d1.
On the development, the second film is dissolved in an alkaline
developer.

[0148] ΔDb represents an absolute value of the difference
between d1 and db, and ΔDb means the amount of film
thickness loss of the first film by exposure at the exposure amount of 40
mJ/cm2.

[0149] (ΔDa-ΔDb) means the amount of film thickness
loss of the first film by heating when the exposure to the first and
second films at the exposure amount of 40 mJ/cm2 is conducted.

[0150] In the step (5), the heating is conducted under the same condition
as that of the heating in the step (3). The development is also conducted
under the same condition as that of the development in the step (3).

[0151] In the step (5), the acid having a group represented by
--C(Q3)(Q4)-SO3H contained in the second film is also
moved in the first and the second films by heating. By moving the acid
having a group represented by --C(Q3)(Q4)-SO3H by heating,
the resin in the first film is contacted with the acid and a part of the
resin in the first film becomes an alkali-soluble and it is dissolved in
an alkaline developer on the development. Therefore, the film thickness
dc becomes smaller than the film thickness d1. On the
development, the second film is dissolved in an alkaline developer.

[0152] ΔDc represents an absolute value of the difference
between d1 and d', and ΔDc means the amount of film
thickness loss of the first film by heating without conducting the
exposure.

[0153] In the step (6), the development is conducted under the same
condition as that of the development in the step (3).

[0154] In the step (6), the acid having a group represented by
--C(Q3)(Q4)-SO3H contained in the second film is contacted
with the first film thereby contacting the resin in the first film with
the acid, and a part of the resin in the first film becomes an
alkali-soluble and it is dissolved in an alkaline developer on the
development. Therefore, the film thickness dd becomes smaller than
the film thickness d1. On the development, the second film is
dissolved in an alkaline developer.

[0155] ΔDd represents an absolute value of the difference
between d1 and dd, and ΔDd means the amount of film
thickness loss of the first film by development.

[0156] (ΔDc-ΔDd) means the amount of film thickness
loss of the first film by heating when the exposure to the first and
second films is not conducted.

[0157] Compound (C1) preferably satisfys that the ratio of the amount of
film thickness loss of the first film by heating when the exposure to the
first and second films at the exposure amount of 40 mJ/cm2 is
conducted to the amount of film thickness loss of the first film by
heating when the exposure to the first and second films is not conducted
((ΔDcΔDb)/(ΔDc-ΔDd)) is 0.2
or more and 0.9 or less. When
(ΔDa-ΔDb)/(ΔDc-ΔDd) is 0.2 or
more and 0.9 or less, the function of trapping the acid by Compound (C1)
is improved by exposure and the acid in the films becomes more difficult
to move in the films. Therefore, the photoresist pattern having better
resolution and better line edge roughness can be obtained. When
(ΔDa-ΔDb)/(ΔDc-ΔDd) is less
than 0.2, the function of trapping the acid by Compound (C1) is improved
too much in the exposed part by exposure and the acid in the films
becomes not to move in the films. Therefore, the photoresist pattern can
not be developed. When
(ΔDa-ΔDb)/(ΔDc-ΔDd) is more
than 0.9, the function of trapping the acid by Compound (C1) in the
exposed part is almost the same as that in the unexposed part, and
therefore, the resolution and the line edge roughness of the photoresist
pattern are not enough to be satisfied.

[0158] Preferable Compound (C1) include Compound (C1) wherein Rc2 and
Rc3 are hydrogen atoms or C1-C6 saturated hydrocarbon groups and
Rc4 and Rc6 and/or RC5 and Rc7 are bonded each other
to form an alkanediyl group, and a compound represented by the formula
(C1-1):

##STR00142##

wherein Rc1 is the same as defined above, and Rc8 and Rc9
independently each represent a C1-C18 alkanediyl group which can have one
or more substituents is more preferable. Rc8 and Rc9 are
preferably unsubstituted C1-C18 alkanediyl groups, and more preferably
C2-C12 alkanediyl groups, and especially preferably C2-C6 alkanediyl
groups.

[0159] Rc8 is preferably a propane-1,3-diyl group. A compound
represented by the formula (C1-1-1) or (C1-1-2):

[0161] The content of Compound (I) is usually 0.01 part by weight or more
per 100 parts of the resin and preferably 0.05 part by weight or more.
The content of Compound (I) is usually 5 parts by weight or less per 100
parts of the resin and preferably 3 parts by weight or less.

[0162] The photoresist compositions of the present invention can contain a
basic compound other than Compound (I) as a quencher.

[0163] The basic compound is preferably a basic nitrogen-containing
organic compound, and examples thereof include an amine compound such as
an aliphatic amine and an aromatic amine and an ammonium salt. Examples
of the aliphatic amine include a primary amine, a secondary amine and a
tertiary amine. Examples of the aromatic amine include an aromatic amine
in which aromatic ring has one or more amino groups such as aniline and a
heteroaromatic amine such as pyridine. Preferable examples thereof
include an aromatic amine represented by the formula (Q1) and the
aromatic amine represented by the formula (Q1-1) is preferable.

##STR00144##

wherein Arq1 represents a C6-C20 aromatic hydrocarbon group, and
Rq1 and Rq2 each independently represent a hydrogen atom, a
C1-C6 aliphatic hydrocarbon group, a C5-C10 alicyclic hydrocarbon group
or a C6-C20 aromatic hydrocarbon group, and the aliphatic hydrocarbon
group and the aromatic hydrocarbon group can have one or more
substituents selected from the group consisting of a hydroxyl group, an
amino group, an amino group having one or two C1-C4 aliphatic hydrocarbon
groups and a C1-C6 alkoxy group, and the aliphatic hydrocarbon group can
have one or more C6-C20 aromatic hydrocarbon groups and the aromatic
hydrocarbon group can have one or more C1-C6 aliphatic hydrocarbon groups
or C5-C10 alicyclic hydrocarbon groups, and the alkoxy group can have one
or more substituents selected from the group consisting of a hydroxyl
group, an amino group, an amino group having one or two C1-C4 aliphatic
hydrocarbon groups and a C1-C6 alkoxy group, Rq3 is independently in
each occurrence a C1-C6 aliphatic hydrocarbon group, a C1-C6 alkoxy
group, a C5-C10 alicyclic hydrocarbon group or a C6-C20 aromatic
hydrocarbon group, and the aliphatic hydrocarbon group, the alkoxy group,
the alicyclic hydrocarbon group and the aromatic hydrocarbon group can
have one or more substituents selected from the group consisting of a
hydroxyl group, an amino group, an amino group having one or two C1-C4
alkyl groups and a C1-C6 alkoxy group, and the aliphatic hydrocarbon
group can have one or more C6-C20 aromatic hydrocarbon groups and the
aromatic hydrocarbon group can have one or more C1-C6 aliphatic
hydrocarbon groups or C5-C10 alicyclic hydrocarbon groups, and the alkoxy
group can have one or more substituents selected from the group
consisting of a hydroxyl group, an amino group, an amino group having one
or two C1-C4 aliphatic hydrocarbon groups and a C1-C6 alkoxy group, and
m3 represents an integer of 0 to 3.

[0164] Examples of the aromatic amine represented by the formula (Q1)
include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline,
2-methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline,
N-methylaniline, N,N-dimethylaniline, and diphenylamine, and among them,
preferred is diisopropylaniline and more preferred is
2,6-diisopropylaniline.

[0165] An quaternary ammonium hydroxide represented by the formula (Q2):

##STR00145##

wherein Rq4, Rq5 and Rq6 independently each represent a
hydrogen atom, a C1-C6 aliphatic hydrocarbon group, a C5-C10 alicyclic
hydrocarbon group or a C6-C20 aromatic hydrocarbon group, and R7
represents a C1-C6 aliphatic hydrocarbon group or a C5-C10 alicyclic
hydrocarbon group, is also preferable. Examples of the aliphatic
hydrocarbon group, the alicyclic hydrocarbon group and the aromatic
hydrocarbon group include the same as described in Rq1 and Rq2,
respectively.

[0167] Other examples of the basic compound include amines represented by
the formulae (Q3) to (Q11):

##STR00146##

wherein Rq8 represents a C1-C6 aliphatic hydrocarbon group or a
C5-C10 alicyclic hydrocarbon group, Rq9 and Rq10 independently
each represent a hydrogen atom, a C1-C6 aliphatic hydrocarbon group or a
C5-C10 alicyclic hydrocarbon group, Rq11 to Rq14, Rq16 to
Rq19, and Rq22 each independently represents a hydrogen atom, a
C1-C6 aliphatic hydrocarbon group, a C5-C10 alicyclic hydrocarbon group
or a C6-C20 aromatic hydrocarbon group, Rq15 is independently in
each occurrence a C1-C6 aliphatic hydrocarbon group, a C3-C6 alicyclic
hydrocarbon group or a C2-C6 alkanoyl group, Rq23 represents a
hydrogen atom, a C1-C6 aliphatic hydrocarbon group, a C1-C6 alkoxy group
or a C5-C10 alicyclic hydrocarbon group, Rq20 to Rq21 and
Rq24 to Rq48 each independently represent a C1-C16 aliphatic
hydrocarbon group, a C5-C10 alicyclic hydrocarbon group, a C1-C6 alkoxy
group or a C6-C20 aromatic hydrocarbon group, and o3 to u3 independently
each represents an integer of 0 to 3, Lq1 and Lq2 each
independently represents a C2-C6 alkanediyl group, --CO--,
--N(Ra29)--, --S--, --S--S-- or a combination thereof and Rq29
represents a hydrogen atom or a C1-C6 aliphatic hydrocarbon group and n3
represents an integer of 0 to 8.

[0168] Examples of the aliphatic hydrocarbon group, the alicyclic
hydrocarbon group and the aromatic hydrocarbon group include the same as
described above.

[0170] Examples of the amine represented by the formula (Q4) include
piperazine. Examples of the amine represented by the formula (Q5) include
morpholine. Examples of the amine represented by the formula (Q6) include
piperidine and hindered amine compounds having a piperidine skeleton as
disclosed in JP 11-52575 A. Examples of the amine represented by the
formula (Q7) include 2,2'-methylenebisaniline. Examples of the amine
represented by the formula (Q8) include imidazole and 4-methylimidazole.
Examples of the amine represented by the formula (Q9) include pyridine
and 4-methylpyridine. Examples of the amine represented by the formula
(Q10) include di-2-pyridyl ketone, 1,2-di(2-pyridyl)ethane,
1,2-di(4-pyridyl)ethane, 1,3-di(4-pyridyl)propane,
1,2-bis(2-pyridyl)ethene, 1,2-bis(4-pyridyl)ethene,
1,2-di(4-pyridyloxy)ethane, 4,4'-dipyridyl sulfide, 4,4'-dipyridyl
disulfide, 2,2'-dipyridylamine and 2,2'-dipicolylamine. Examples of the
amine represented by the formula (Q11) include bipyridine.

[0171] When the basic compound is used, the total content of Compound (C1)
and the basic compound is preferably 5 parts by weight or less per 100
parts by weight of the resin, and preferably 3 parts by weight or less.
The total content of Compound (C1) and the basic compound is preferably
0.01 part by weight or more per 100 parts by weight of the resin, and
preferably 0.05 parts by weight or more.

[0172] The photoresist compositions of the present invention usually
contain one or more solvents. Examples of the solvent include a glycol
ether ester such as ethyl cellosolve acetate, methyl cellosolve acetate
and propylene glycol monomethyl ether acetate; a glycol ether such as
propylene glycol monomethyl ether; an acyclic ester such as ethyl
lactate, butyl acetate, amyl acetate and ethyl pyruvate; a ketone such as
acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; and a
cyclic ester such as γ-butyrolactone.

[0173] The amount of the solvent is usually 50% by weight or more,
preferably 70% by weight or more, and especially preferably 90% by weight
or more based on total amount of the photoresist composition of the
present invention. The amount of the solvent is usually 99% by weight or
less and preferably 97% by weight or less based on total amount of the
photoresist composition of the present invention.

[0174] The photoresist compositions of the present invention can contain,
if necessary, a small amount of various additives such as a sensitizer, a
dissolution inhibitor, other polymers, a surfactant, a stabilizer and a
dye as long as the effect of the present invention is not prevented.

[0175] The photoresist compositions of the present invention are useful
for a chemically amplified photoresist composition.

[0176] A photoresist pattern can be produced by the following steps (1) to
(5):

[0177] (1) a step of applying the photoresist composition of the present
invention on a substrate,

[0178] (2) a step of forming a photoresist film by conducting drying,

[0179] (3) a step of exposing the photoresist film to radiation,

[0180] (4) a step of baking the exposed photoresist film, and

[0181] (5) a step of developing the baked photoresist film with an
alkaline developer, thereby forming a photoresist pattern.

[0182] The applying of the photoresist composition on a substrate is
usually conducted using a conventional apparatus such as spin coater. The
photoresist composition is preferably filtrated with filter having 0.2
μm of a pore size before applying. Examples of the substrate include a
silicon wafer or a quartz wafer on which a sensor, a circuit, a
transistor or the like is formed.

[0183] The formation of the photoresist film is usually conducted using a
heating apparatus such as hot plate or a decompressor, and the heating
temperature is usually 50 to 200° C., and the operation pressure
is usually 1 to 1.0*105 Pa.

[0184] The photoresist film obtained is exposed to radiation using an
exposure system. The exposure is usually conducted through a mask having
a pattern corresponding to the desired photoresist pattern. Examples of
the exposure source include a light source radiating laser light in a
UV-region such as a KrF excimer laser (wavelength: 248 nm), an ArF
excimer laser (wavelength: 193 nm) and a F2 laser (wavelength: 157
nm), and a light source radiating harmonic laser light in a far UV region
or a vacuum UV region by wavelength conversion of laser light from a
solid laser light source (such as YAG or semiconductor laser).

[0185] The temperature of baking of the exposed photoresist film is
usually 50 to 200° C., and preferably 70 to 150° C.

[0186] The development of the baked photoresist film is usually carried
out using a development apparatus. The alkaline developer used may be any
one of various alkaline aqueous solution used in the art. Generally, an
aqueous solution of tetramethylammonium hydroxide or
(2-hydroxyethyl)trimethylammoniumhydroxide (commonly known as "choline")
is often used. After development, the photoresist pattern formed is
preferably washed with ultrapure water, and the remained water on the
photoresist pattern and the substrate is preferably removed.

[0188] The present invention will be described more specifically by
Examples, which are not construed to limit the scope of the present
invention.

[0189] The "%" and "part(s)" used to represent the content of any
component and the amount of any material used in the following examples
and comparative examples are on a weight basis unless otherwise
specifically noted. The weight-average molecular weight of any material
used in the following examples is a value found by gel permeation
chromatography [HLC-8120GPC Type, Column (Three Columns): TSKgel
Multipore HXL-M, manufactured by TOSOH CORPORATION, Solvent:
tetrahydrofuran] using standard polystyrene as a standard reference
material. Structures of compounds were determined by NMR (GX-270 Type or
EX-270 Type, manufactured by JEOL LTD.) and mass spectrometry (Liquid
Chromatography: 1100 Type, manufactured by AGILENT TECHNOLOGIES LTD.,
Mass Spectrometry: LC/MSD Type or LC/MSD TOF Type, manufactured by
AGILENT TECHNOLOGIES LTD.).

[0191] Monomer (a1-1-1), Monomer (a1-2-1), Monomer (a2-1-2) and Monomer
(a3-2-1) were mixed at a molar ratio of 40:10:10:40 (Monomer
(a1-1-1):Monomer (a1-2-1):Monomer (a2-1-2):Monomer (a3-2-1)), and
1,4-dioxane in 1.2 times weight based on all monomers was added thereto,
to prepare solution. To the solution, azobisisobutyronitrile as an
initiator in a ratio of 1 mol % based on all monomer molar amount, and
azobis (2,4-dimethylvaleronitrile) as an initiator in a ratio of 3 mol %
based on all monomer molar amount were added. The obtained mixture was
heated at 75° C. for about 5 hours. Then, the reaction solution
was poured into large amount of a mixture of methanol and water to cause
precipitation. The precipitate was isolated, and was poured into large
amount of a mixture of methanol and water to purify the precipitation,
and this operation was repeated three times for purification. As a
result, a resin having a weight-average molecular weight of 7402 was
obtained in a yield of 74%. This is called as Resin A1. Resin A1 had the
structural units derived from Monomer (a1-1-1), Monomer (a1-2-1), Monomer
(a2-1-2) and Monomer (a3-2-1).

Resin Synthesis Example 2

[0192] Monomer (a1-1-2), Monomer (a2-1-1) and Monomer (a3-1-1) were mixed
at a molar ratio of 50:25:25 (Monomer (a1-1-2):Monomer (a2-1-1):Monomer
(a3-1-1)), and 1,4-dioxane in 1.5 times weight based on all monomers was
added thereto, to prepare solution. To the solution,
azobisisobutyronitrile as an initiator in a ratio of 1 mol % based on all
monomer molar amount, and azobis(2,4-dimethylvaleronitrile) as an
initiator in a ratio of 3 mol % based on all monomer molar amount were
added. The obtained mixture was heated at 77° C. for about 5
hours. Then, the reaction solution was poured into large amount of a
mixture of methanol and water to cause precipitation. The precipitate was
isolated, and was poured into large amount of a mixture of methanol and
water to purify the precipitation, and this operation was repeated three
times for purification. As a result, a resin having a weight-average
molecular weight of 8112 was obtained in a yield of 55%. This is called
as Resin A2. Resin A2 had the structural units derived from Monomer
(a1-1-2), Monomer (a2-1-1) and Monomer (a3-1-1).

Resin Synthesis Example 3

[0193] Monomer (a1-1-2) and Monomer (a3-1-1) were mixed at a molar ratio
of 55:45 (Monomer (a1-1-2):Monomer (a3-1-1)), and the polymerization
reaction was conducted according to the method described in US
2003/0017415 A1 to obtain a resin having a weight-average molecular
weight of 11000. This is called as Resin A3. Resin A3 had the structural
units derived from Monomer (a1-1-2) and Monomer (a3-1-1).

Resin Synthesis Example 4

[0194] Monomer (a1-1-1), Monomer (a1-2-1), Monomer (a2-1-1), Monomer
(a3-1-1) and Monomer (a3-2-1) were mixed at a molar ratio of
30:14:6:30:20 (Monomer (a1-1-1):Monomer (a1-2-1):Monomer (a2-1-1):Monomer
(a3-1-1):Monomer (a3-2-1)), and 1,4-dioxane in 1.5 times weight based on
all monomers was added thereto, to prepare solution. To the solution,
azobisisobutyronitrile as an initiator in a ratio of 1 mol % based on all
monomer molar amount, and azobis(2,4-dimethylvaleronitrile) as an
initiator in a ratio of 3 mol % based on all monomer molar amount were
added. The obtained mixture was heated at 73° C. for about 5
hours. Then, the reaction solution was poured into large amount of a
mixture of methanol and water to cause precipitation. The precipitate was
isolated, and was poured into large amount of a mixture of methanol and
water to purify the precipitation, and this operation was repeated three
times for purification. As a result, a resin having a weight-average
molecular weight of 8100 was obtained in a yield of 65%. This is called
as Resin A4. Resin A4 had the structural units derived from Monomer
(a1-1-1), Monomer (a1-2-1), Monomer (a2-1-1), Monomer (a3-1-1) and
Monomer (a3-2-1).

Resin synthesis Example 5

[0195] Monomer (S) was mixed with 1,4-dioxane of which amount was twice
weight based on the monomer. To the mixture, azobisisobutyronitrile as an
initiator in a ratio of 1 mol % based on all monomer molar amount, and
azobis (2,4-dimethylvaleronitrile) as an initiator in a ratio of 3 mol %
based on all monomer molar amount were added. The obtained mixture was
heated at 73° C. for about 5 hours. Then, the reaction solution
was poured into a large amount of heptane to cause precipitation. The
precipitate was isolated, and was poured into large amount of methanol to
purify the precipitation, and this operation was repeated three times for
purification. As a result, a resin having a weight-average molecular
weight of about 2.2×104 was obtained in a yield of 95%. This
is called as Resin S1. Resin S1 had the structural units derived from
Monomer (S).

Reference Example 1

[0196] The following components were mixed to prepare a solution, and the
solution was filtrated through a fluorine resin filter having pore
diameter of 0.2 μm, to prepare Composition (1).

[1] Silicon wafer having a diameter of 12 inches was coated with
Composition (1) so that the thickness of the resulting film became 300 nm
after drying. The silicon wafer thus coated with Composition (1) was
heated on a direct hotplate at 85° C. for 60 seconds to prepare
the first film. The film thickness d1 of the first film was measured
with a contactless film thickness measurement "Lambda Ace" manufactured
by DAINIPPON SCREEN MFG. CO. LTD. [2] Composition (2) was spin-coated on
the first film. The silicon wafer was heated on a direct hotplate at
85° C. for 60 seconds to prepare the second film on the first
film. [3] The first and second films on the silicon wafer obtained [2]
was exposed with an ArF immersion excimer stepper ("XT-1900Gi"
manufactured by ASML, NA=1.35, 3/4 Annular, X-Y deflection) at the
exposure amount of 40 mJ/cm2. The obtained wafer was subjected to
the heating on a hotplate at 85° C. for 60 seconds and then to
paddle development for 60 seconds with an aqueous solution of 2.38%
tetramethylammonium hydroxide. The film thickness da of the first
film was measured with a contactless film thickness measurement "Lambda
Ace" manufactured by DAINIPPON SCREEN MFG. CO. LTD. [4] The first and
second films on the silicon wafer obtained [2] was exposed with an ArF
immersion excimer stepper ("XT-1900Gi" manufactured by ASML, NA=1.35, 3/4
Annular, X-Y deflection) at the exposure amount of 40 mJ/cm2. The
obtained wafer was subjected to paddle development for 60 seconds with an
aqueous solution of 2.38% tetramethylammonium hydroxide. The film
thickness db of the first film was measured with a contactless film
thickness measurement "Lambda Ace" manufactured by DAINIPPON SCREEN MFG.
CO. LTD. [5] The first and second films on the silicon wafer obtained [2]
was heated on a hotplate at 85° C. for 60 seconds and then, was
subjected to paddle development for 60 seconds with an aqueous solution
of 2.38% tetramethylammonium hydroxide. The film thickness dc of the
first film was measured with a contactless film thickness measurement
"Lambda Ace" manufactured by DAINIPPON SCREEN MFG. CO. LTD. [6] The first
and second films on the silicon wafer obtained [2] was subjected to
paddle development for 60 seconds with an aqueous solution of 2.38%
tetramethylammonium hydroxide. The film thickness dd of the first
film was measured with a contactless film thickness measurement "Lambda
Ace" manufactured by DAINIPPON SCREEN MFG. CO. LTD.

[0199] ΔDa, ΔDb, ΔDc and ΔDd
were calculated based on the film thickness da, db, dd and
dd, and the results are shown in Tables 1 to 3.

Reference Example 2

[0200] Composition (3) was prepared according to the same manner of
Example 1 except that Compound C7
(5-(4-methoxycarbonylbenzyl)-1,8-diazabicyclo[5.4.0]undecane, which is
described in WO 2008/119688 A) was used in place of Compound C6, and
ΔDa, ΔDb, ΔDC and ΔDd were
calculated based on the film thickness d1, da, dc and
dd, and the results are shown in Tables 1 to 3.

Reference Example 3

[0201] Composition (4) was prepared according to the same manner of
Example 1 except that Q1 (2,6-diisopropylaniline) was used in place of
Compound C6, and ΔDa, ΔDb, ΔDC and
ΔDd were calculated based on the film thickness d1,
da, db, dc and dd, and the results are shown in
Tables 1 to 3.

[0203] C1: 5-benzyl-1,5-diazabicyclo[4.3.0]nonane, which is described in
JP 2005-511536 A C2: 5-(2-chlorobenzyl)-1,5-diazabicyclo[4.3.0]nonane,
which is described in JP 2005-511536 A C3:
5-(4-methylbenzyl)-1,5-diazabicyclo[4.3.0]nonane, which is described in
JP 2005-511536 A C4: 8-benzyl-1,8-diazabicyclo[5.4.0]undecane, which is
described in JP 2005-511536 A C5:
8-(2-chlorobenzyl)-1,8-diazabicyclo[5.4.0]undecane, which is described in
JP 2005-511536 A C6: 5-(2-nitrobenzyl)-1,8-diazabicyclo[5.4.0]undecane,
which is described in JP 2005-511536 A C7:
5-(4-methoxycarbonylbenzyl)-1,8-diazabicyclo[5.4.0]undecane, which is
described in WO 2008/119688 A

[0206] The following components were mixed and dissolved, further,
filtrated through a fluorine resin filter having pore diameter of 0.2
μm, to prepare photoresist compositions. [0207] Resin (kind and
amount are described in Table 4) [0208] Acid generator (kind and amount
are described in Table 4) [0209] Compound (C1) (kind and amount are
described in Table 4) [0210] Quencher (kind and amount are described in
Table 4) [0211] Solvent D1

[0212] Silicon wafers having a diameter of 12 inches were each coated with
"ARC-29", which is an organic anti-reflective coating composition
available from Nissan Chemical Industries, Ltd., and then baked under the
conditions of 205° C. and 60 seconds, to form a 780 Å-thick
organic anti-reflective coating. Each of the photoresist compositions
prepared as above was spin-coated over the anti-reflective coating so
that the thickness of the resulting film became 85 nm after drying. The
silicon wafers thus coated with the respective photoresist compositions
were each prebaked on a direct hotplate at a temperature shown in column
of "PB" of Table 4 for 60 seconds. Using an ArF immersion excimer stepper
("XT-1900Gi" manufactured by ASML, NA=1.35), each wafer thus formed with
the respective photoresist film was subjected to contact hole pattern
immersion exposure using photomasks for forming a contact hole pattern
having a hole pitch of 100 nm and a hole diameters of 40 to 72 nm, with
the exposure quantity being varied stepwise.

[0213] After the exposure, each wafer was subjected to post-exposure
baking on a hotplate at a temperature shown in column of "PEB" of Table 4
for 60 seconds and then to paddle development for 60 seconds with an
aqueous solution of 2.38% tetramethylammonium hydroxide.

[0214] Each of contact hole patterns developed on the organic
anti-reflective coating substrate after the development was observed with
a scanning electron microscope, the results of which are shown in Tables
5.

[0215] Effective Sensitivity (ES): It is expressed as the amount of
exposure that the hole diameter of the contact hole pattern become 55 nm
after exposure through a photomask for forming a contact hole pattern
having a hole diameters of 70 nm and development.

[0216] CD uniformity (CDU): The photoresist patterns were obtained using a
photomask for forming a hole pattern having a hole diameter of 70 nm at
the exposure amount of ES. Each of patterns developed on the organic
anti-reflective coating substrate after the development was observed with
a scanning electron microscope. The hole diameter of the hole patterns
was twenty four times measured and its average diameter was calculated.
The average diameters of four hundred holes on the same wafer were
respectively measured. When population was the average diameters of four
hundred holes, the standard deviation was calculated. When the standard
deviation is 1.80 nm or more and 2.00 nm or less, CDU is normal and its
evaluation is marked by "Δ", when the standard deviation is less
than 1.80 nm, CDU is good and its evaluation is marked by
"◯", and when the standard deviation is more than 2.00 nm,
CDU is bad and its evaluation is marked by "X". The smaller the standard
deviation is, the better CDU the photoresist pattern shows.

[0217] Focus margin (DOF): The photoresist patterns were obtained using a
hole-patterned photomask at the exposure amount of ES, with the focal
point distance being varied stepwise. Each of patterns developed on the
organic anti-reflective coating substrate after the development were
observed and the focal point distances when the patterns of which hole
diameter was 52.2 nm or more and 57.7 nm or less were measured and the
difference between the max value of the focal point distance and the
minimum value of the focal point distance was calculated. When the
difference is 0.16 μm or more and 0.20 μm or less, DOF is normal
and its evaluation is marked by "Δ", when the difference is more
than 0.20 μm, DOF is good and its evaluation is marked by
"◯", and when the difference is less than 0.16 μm, DOF is
bad and its evaluation is marked by "X". The difference is bigger, the
better focus margin the photoresist composition has.

[0218] Mask Error Enhancement Factor (MEEF): Hole diameters of each hole
patterns exposed at ES using photomasks for forming a hole pattern having
pitch of 100 nm and hole diameter of 67 to 72 nm with 1 nm increments in
between and developed were measured. A graph wherein the hole diameter of
used photomask is a vertical axis and the hole diameter of the obtained
hole patterns is a horizontal axis was made and the straight line was
drawn. MEEF was expressed as the value of the slope of the straight line.
When the value of the slope was 2.8 or more and 3.1 or less, MEEF is
normal and its evaluation is marked by "Δ", when the value of the
slope was less than 2.8, MEEF is good and its evaluation is marked by
"◯", and when the value of the slope was more than 3.1, MEEF
is bad and its evaluation is marked by "X". The closer the value of the
slope is to 1, the better MEEF is.

[0219] Pattern Shape: The hole pattern obtained by using the photomask for
forming a hole pattern of which hole diameter is 70 nm was observed with
a scanning electron microscope, and when a cross-section of the pattern
is as shown in the following (a), pattern profile is good and its
evaluation is marked by "◯", when a cross-section of the
pattern is as shown in the following (b), (c) or (d), pattern profile is
bad, and its evaluation is marked by "X".

##STR00151##

[0220] Silicon wafers having a diameter of 12 inches were each coated with
"ARC-29", which is an organic anti-reflective coating composition
available from Nissan Chemical Industries, Ltd., and then baked under the
conditions of 205° C. and 60 seconds, to form a 780 Å-thick
organic anti-reflective coating. Each of the photoresist compositions
prepared as above was spin-coated over the anti-reflective coating so
that the thickness of the resulting film became 85 nm after drying. The
silicon wafers thus coated with the respective photoresist compositions
were each prebaked on a direct hotplate at a temperature shown in column
of "PB" of Table 4 for 60 seconds. Using an ArF immersion excimer stepper
("XT-1900Gi" manufactured by ASML, NA=1.35, 3/4 Annular, X-Y deflection),
each wafer thus formed with the respective photoresist film was subjected
to line and space pattern immersion exposure, with the exposure quantity
being varied stepwise.

[0221] After the exposure, each wafer was subjected to post-exposure
baking on a hotplate at a temperature shown in column of "PEB" of Table 4
for 60 seconds and then to paddle development for 60 seconds with an
aqueous solution of 2.38% tetramethylammonium hydroxide.

[0222] Each of line and space patterns developed on the organic
anti-reflective coating substrate after the development was observed with
a scanning electron microscope, the results of which are shown in Tables
5.

[0223] Effective Sensitivity (ES): It was expressed as the amount of
exposure that the line and space pattern of 50 nm became 1:1 after
exposure through line and space pattern mask and development.

[0224] Resolution: The line and space patterns were obtained using a line
and space photomask at the exposure amount of ES, and were observed with
a scanning electron microscope. When 45 nm line and space pattern was
resolved, resolution is good and its evaluation is marked by
"◯", and when 45 nm line and space pattern was not resolved,
resolution is bad and its evaluation is marked by "X".

[0225] Line Edge Roughness (LER): The photoresist pattern at the exposure
dose that the line pattern and the space pattern become 1:1 after
exposure through 50 nm line and space pattern mask and development was
observed with a scanning electron microscope. The difference between the
height of the highest point and height of the lowest point of the
scabrous wall surface of the photoresist pattern was measured. When the
difference is 5 nm or less, LER is good and its evaluation is marked by
"◯", and when the difference is more than 5 nm, LER is bad
and its evaluation is marked by "X". The smaller the difference is, the
better the pattern is.